Information processing device and method, transmitting device and method, and receiving device and method

ABSTRACT

An information processing device and method, a transmitting device and method, and a receiving device and method are disclosed for multiplexing transmission signals in the same channel. In one example, transmission signals are generated by performing chirp modulation on data to be transmitted, and the transmission signals are multiplexed by shifting transmission timings of a plurality of transmission signals in a time direction and transmitting the transmission signals. Further, a plurality of chirp-modulated transmission signals which are multiplexed by shifting the transmission timing in the time direction and transmitted from a transmission side are received, and the plurality of received transmission signals are dechirped at timings according to the transmission timings.

CROSS REFERENCE TO RELATED APPLICATIONS

This present application is a Divisional of application Ser. No.15/740,508, filed Dec. 28, 2017, which is a 371 Nationalization ofPCT/JP 2017-016262, filed Apr. 25, 2017, which claims priority toJapanese Priority Patent Applications JP 2016-114358 filed Jun. 8, 2016and JP 2016-138365 filed Jul. 13, 2016, the entire contents of which areincorporated herein by reference.

TECHNICAL FIELD

The present technology relates to an information processing device andmethod, a transmitting device and method, and a receiving device andmethod, and more particularly to, an information processing device andmethod, a transmitting device and method, and a receiving device andmethod, which are capable of multiplexing transmission signals in thesame channel.

BACKGROUND ART

In the past, as signal multiplexing methods, frequency divisionmultiplexing (FDM), time division multiplexing (TDM), spread spectrum,and the like have been known (see, for example, Patent Document 1). Inaddition, as a modulation method for transmission signals, a method ofperforming chirp modulation on a phase modulation signal is considered(see, for example, Patent Document 2).

CITATION LIST Patent Document

-   Patent Document 1: Japanese Patent No. 3270902-   Patent Document 2: Japanese Patent Application Laid-Open No.    08-307375

SUMMARY OF THE INVENTION Problems to be Solved by the Invention

However, in the case of the frequency division multiplexing (FDM), in a920 MHz band of Japan, it is necessary to adjust a center frequencywithin ±20 ppm, and it is unable to be used practically. Further, in thecase of the time division multiplexing (TDM), sufficiently highmultiplicity is unable to be obtained. For example, in a case wheretransmission is performed for 4 seconds once per minute, only 12multiples are obtained. Further, in the case of the spread spectrum,spreading is performed using a random number sequence, transmission isperformed, and a receiver is able to perform separation by integratingwhile multiplying by the random number sequence. However,cross-correlation portions of the random number sequence are likely toundergo interference. Further, multiplexing of chirp-modulatedtransmission signals is not disclosed in Patent Document 2.

The present technology was made in light of the foregoing, and it is anobject of the present technology to multiplex a transmission signal inthe same channel.

Solutions to Problems

An information processing device of a first aspect of the presenttechnology, includes: a supplying unit that supplies a plurality ofreceiving devices with identification information of a transmittingdevice, the plurality of receiving devices receiving informationtransmitted from the transmitting device that multiplexes a plurality oftransmission signals generated by performing chirp modulation ontransmission data in the same transmission channel by shifting atransmission timing at predetermined time intervals and transmits themultiplexed transmission signals, the identification information of thetransmitting device being used for a setting for receiving thetransmission signals in each of the receiving devices.

A transmitting device of a second aspect of the present technology,includes: a chirp modulating unit that performs chirp modulation ontransmission data; a transmitting unit that multiplexes a plurality oftransmission signals generated by performing the chirp modulation in thesame transmission channel by shifting a transmission timing atpredetermined time intervals and transmits the multiplexed transmissionsignals; and a control unit that sets the transmission timing and thetransmission channel on the basis of identification information of thetransmitting device.

A receiving device of a third aspect of the present technology,includes: a receiving unit that receives transmission signalstransmitted from a transmitting device that multiplexes a plurality oftransmission signals generated by performing the chirp modulation in thesame transmission channel by shifting a transmission timing atpredetermined time intervals and transmits the multiplexed transmissionsignals; a dechirping unit that dechirps the transmission signals; acontrol unit that sets a reception channel of the transmission signalson the basis of identification information of the transmitting deviceand sets a reception timing according to the transmission timing of eachof the plurality of transmission signals.

In the first aspect of the present technology, a plurality of receivingdevices are supplied with identification information of a transmittingdevice, the plurality of receiving devices receiving informationtransmitted from the transmitting device that multiplexes a plurality oftransmission signals generated by performing chirp modulation ontransmission data in the same transmission channel by shifting atransmission timing at predetermined time intervals and transmits themultiplexed transmission signals, the identification information of thetransmitting device being used for a setting for receiving thetransmission signals in each of the receiving devices.

In the second aspect of the present technology, chirp modulation isperformed on transmission data, a plurality of transmission signalsgenerated by performing the chirp modulation in the same transmissionchannel are multiplexed by shifting a transmission timing atpredetermined time intervals and transmitted, and the transmissiontiming and the transmission channel are set on the basis ofidentification information of the transmitting device.

In the third aspect of the present technology, transmission signalstransmitted from a transmitting device that multiplexes a plurality oftransmission signals generated by performing the chirp modulation in thesame transmission channel by shifting a transmission timing atpredetermined time intervals and transmits the multiplexed transmissionsignals are received, the transmission signals are dechirped, areception channel of the transmission signals is set on the basis ofidentification information of the transmitting device, and a receptiontiming according to the transmission timing of each of the plurality oftransmission signals is set.

Effects of the Invention

According to the present technology, it is possible to transmit orreceive signals. Further, according to the present technology, it ispossible to multiplex transmission signals in the same channel.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a diagram illustrating an example of an aspect of chirpmodulation.

FIG. 2 is a diagram illustrating an example of an aspect ofmultiplexing.

FIG. 3 is a diagram illustrating an example of an aspect ofmultiplexing.

FIG. 4 is a diagram illustrating a main configuration example of aposition notification system.

FIG. 5 is a diagram for describing an example of an aspect of positionnotification.

FIG. 6 is a block diagram illustrating a main configuration example ofthe transmitting device.

FIG. 7 is a diagram illustrating a main configuration example of a BPSKmodulating unit.

FIG. 8 is a diagram illustrating a main configuration example of a chirpgenerating unit.

FIG. 9 is a diagram illustrating a main configuration example of atiming controller.

FIG. 10 is a diagram illustrating an example of an aspect of anoperation of a timing controller.

FIG. 11 is a flowchart for describing an example of a flow of atransmission process.

FIG. 12 is a block diagram illustrating a main configuration example ofa high sensitivity receiving device.

FIG. 13 is a diagram illustrating a main configuration example of atiming controller.

FIG. 14 is a diagram illustrating an example of an aspect of anoperation of a timing controller.

FIG. 15 is a flowchart for describing an example of a flow of areception process.

FIG. 16 is a block diagram illustrating a main configuration example ofa transmitting device.

FIG. 17 is a diagram illustrating an example of a chirp signal.

FIG. 18 is a diagram illustrating an example of a chirp signal.

FIG. 19 is a diagram illustrating a main configuration example of anantitheft system.

FIG. 20 is a diagram for describing an example of an aspect oftransmission.

FIG. 21 is a diagram for describing an example of an aspect oftransmission.

FIG. 22 is a diagram for describing an example of an aspect oftransmission.

FIG. 23 is a diagram for describing an example of an aspect oftransmission.

FIG. 24 is a diagram for describing an example of an aspect of theoccurrence of interference.

FIG. 25 is a diagram illustrating a main configuration example of aposition notification system.

FIG. 26 is a diagram for describing a main configuration example of aserver.

FIG. 27 is a functional block diagram illustrating an example of afunction implemented by a CPU.

FIG. 28 is a block diagram illustrating a main configuration example ofa transmitting device.

FIG. 29 is a block diagram illustrating a main configuration example ofa base station.

FIG. 30 is a functional block diagram illustrating an example of afunction implemented by a CPU.

FIG. 31 is a flowchart illustrating an example of a flow of managementprocess.

FIG. 32 is a flowchart illustrating an example of a flow of atransmission process.

FIG. 33 is a flowchart illustrating an example of a flow of a receptionprocess.

FIG. 34 is a flowchart illustrating an example of a flow of receptionprocess.

FIG. 35 is a flowchart illustrating an example of a flow of a collisiondetermination process.

FIG. 36 is a diagram illustrating an update example of a priority list.

FIG. 37 is a diagram illustrating a main configuration example of anantitheft system.

FIG. 38 is a block diagram illustrating a main configuration example ofa computer.

MODE FOR CARRYING OUT THE INVENTION

Hereinafter, modes for carrying out the present disclosure (hereinafterreferred to as “embodiments”) will be described. Further, thedescription will proceed in the following order.

-   -   1. First embodiment (position notification system)    -   2. Second embodiment (application example)    -   3. Third embodiment (others)    -   4. Fourth embodiment (position notification system)    -   5. Fifth embodiment (antitheft system)

1. First Embodiment

<Multiplexing of Chirp Modulation>

In order to multiplex transmission signals in the same channel of a 920MHz band in Japan, chirp modulation is performed on transmission signalsof packets, and transmission timings of a plurality of chirp-modulatedtransmission signals are shifted in a time direction. An example of thisaspect is illustrated in FIG. 1. In FIG. 1, a main signal (for example,a transmission signal) is chirp-modulated. A center frequency is 925MHz, a duration is 0.2 seconds, and a chirp width (Chirp BW) is 101.562KHz. More specifically, a chirp rate (Chirp Rate) of the main signal is6.348 KHz, a change of 79.98 Hz is implemented by 6 μS pitch×25.9 steps,and 157.7 μs is taken.

As illustrated in FIG. 2, if a transmission timing of an adjacentinterfering wave is 0.02 sec shifted from the transmission timing of themain signal for the main signal (chirp-modulated transmission signal),the main signal and an interfering waves thereof are multiplexed so thatthey can be separated (with no interference).

If the transmission timing is shifted in the time direction using such aprinciple, a plurality of chirp-modulated transmission signals can bemultiplexed so that they can be separated (with no interference) asillustrated in FIG. 3. In other words, the transmission signals can bemultiplexed in the same channel of the 920 MHz band in Japan. In the 920MHz band in Japan, a plurality of channels having a predeterminedbandwidth are specified.

Further, as illustrated in FIG. 1, the chirp-modulated transmissionsignal may start to be transmitted at a time known to a reception side.In other words, the transmission timing of each transmission signal maybe set to the known time (also referred to as a “grid time”).Accordingly, each transmission signal can be more easily detected on thereception side.

In other words, in the examples of FIGS. 2 and 3, transmission of eachtransmission signal may be similarly started at the grid time. Further,an interval of the grid time may be constant. Further, the interval ofthe grid time may be shorter than a chirp modulation cycle. For example,in the example of FIG. 3, the chirp modulation cycle is identical to 0.2seconds, that is, a transmission time of one packet. Further, theinterval of the grid time is 0.02 seconds.

Further, the chirp-modulated transmission signal may further undergonarrow band modulation as illustrated in FIG. 1. If the narrow bandmodulation is performed on the transmission data, a bandwidth of themain signal can be set to 10 KHz or less. As illustrated in FIG. 2, asthe bandwidth of each chirp-modulated transmission signal is narrower,it is possible to bring the transmission signals closer to each other,and thus more transmission signals can be multiplexed, for example, asillustrated in FIG. 3. Further, the accuracy of synchronizationdetection can be improved.

As the narrow band modulation, for example, phase shift modulation suchas binary phase shift keying (BPSK) or quadrature phase shift keying(QPSK) maybe applied, or minimum shift modulation such as Gaussianfiltered minimum shift keying (GMSK) may be applied.

By employing such modulation schemes, it is possible to generate thetransmission signal through a PLL. Therefore, it is possible to suppressan increase in power consumption. Further, it is possible to apply ahigh-efficient amplifying unit to amplification of the transmissionsignal accordingly.

Further, the transmission timing of the chirp-modulated transmissionsignal may be controlled on the basis of time information included in aGPS signal. Accordingly, it is possible to control the transmissiontiming of the chirp-modulated transmission signal with a high degree ofaccuracy.

Further, reception of the GPS signal and transmission of thechirp-modulated transmission signal may be performed on the basis of acommon reference clock signal. In this case, the reference clock maydeviate from the time information of the GPS signal. Therefore, thedeviation (frequency deviation) may be corrected. Accordingly, it ispossible to control the transmission timing of the chirp-modulatedtransmission signal with a high degree of accuracy.

In a case where a plurality of multiplexed chirp-modulated transmissionsignals which are transmitted at different transmission timings from thetransmission side as described above are received, each transmissionsignal is dechirped at timing corresponding to each transmission timing.Accordingly, it is possible to separate and demodulate each transmissionsignal (each packet) (with no interference). In other words, it ispossible to implement multiplexing of the transmission signals withinthe same channel of the 920 MHz band in Japan.

As described above, the transmission timing of each transmission signalmay be set to the known time (the grid time). Further, an interval of atiming at which each transmission signal is dechirped may be fixed.Further, the interval of the timing at which each transmission signal isdechirped may be shorter than the chirp modulation cycle.

Further, the narrow band modulation may further be performed on thechirp-modulated transmission signal, and narrow band demodulation mayfurther be performed on the transmission signal after the transmissionsig is dechirped. As the narrowband demodulation, for example, phasedisplacement demodulation such as BPSK, QPSK, or the like may beapplied, or minimum deviation demodulation such as GMSK may be applied.

Further, the dechirp timing control for the chirp-modulated transmissionsignal may be performed on the basis of a predetermined synchronizationsignal. Further, it may be performed on the basis of the GPS signal aswell. Further, delay correction may be performed on the dechirp timingof the chirp-modulated transmission signal.

<Position Notification System>

Next, a system and a device to which the present technology is appliedwill be described. FIG. 4 is a diagram illustrating a main configurationexample of a position notification system which is one example of asignal transmission/reception system to which the present technology isapplied. A position notification system 100 illustrated in FIG. 4 is asystem in which a transmitting device 101 gives a notificationindicating its position.

The transmitting device 101 is an example of a transmitting device towhich the present technology is applied, and transmits positioninformation indicating its position as a radio signal. A highsensitivity receiving device 102 is an example of a receiving device towhich the present technology is applied and receives the radio signal,acquires the position information of the transmitting device 101, andsupplies the position information to a server 104 via a network 103. Inother words, the high sensitivity receiving device 102 functions as arelay station which relays information transmitted from the transmittingdevice 101 and transmits the information to the server 104. Thetransmission of the information from the transmitting device 101 to thehigh sensitivity receiving device 102 is performed, for example, throughone-way communication. The server 104 manages the position informationof each transmitting device 101. A terminal device 105 operated by auser who desires to know the position of the transmitting device 101accesses the server 104 via the network 103, acquires the positioninformation of the transmitting device 101 from the server 104, andnotifies the user of the position of the transmitting device 101, forexample, by displaying the position information together with map dataor the like.

For example, the transmitting device 101 is carried by a subject whomthe user desires to know the position. In the example of FIG. 4, thetransmitting device 101 is carried by an elderly person 111. Thetransmitting device 101 is able to obtain its position information (forexample, a latitude and a longitude) appropriately, for example, byreceiving GNSS signals from global navigation satellite system (GNSS)satellites. The transmitting device 101 appropriately transmits itsposition information as the radio signal. Therefore, the user is able toknow the position of the elderly person 111 who is a position monitoringsubject by operating the terminal device 105 as described above.

Further, the position monitoring subject is arbitrary. For example, theposition monitoring subject may be a child, an animal such as a dog or acat, or an employee of a company. The transmitting device 101 may beconfigured as a dedicated device or may be incorporated into, forexample, a mobile information processing device such as a mobile phoneor a smartphone.

An installation position of the high sensitivity receiving device 102 isarbitrary. For example, the installation position may be a roof or arooftop of a structure 112 such as a building, a condominium, a house,or the like. The structure 112 is preferable because there are manystructures in an urban area in which the position monitoring subjectcarrying the transmitting device 101 (for example elderly person 111) islikely to act, and it is easy to install. Particularly, the home of theposition monitoring subject is suitable since the position monitoringsubject is more likely to stay therearound. Further, from a point ofview of securing an installation place, it is easier to obtain consentas compared with a case where the high sensitivity receiving device 102is installed in a place independently secured by a position notificationservice provider.

Further, for example, when the position monitoring subject (or the user)purchases or borrows and installs the high sensitivity receiving device102, it is possible to reduce a load (cost) on the position notificationservice provider as compared with a case where the position notificationservice provider independently installs the high sensitivity receivingdevice 102. In other words, accordingly, it is possible to install morehigh sensitivity receiving devices 102 at a lower cost.

In a state in which the transmitting device 101 is located within acommunication coverage of any one of the high sensitivity receivingdevices 102, the server 104 is able to manage the position of thetransmitting device 101. In other words, if the position of thetransmitting device 101 is out of the communication coverage of any oneof the high sensitivity receiving device 102, the server 104 is unableto manage the position. Therefore, as the communication coverage networkwith the transmitting device 101 of the high sensitivity receivingdevice 102 has a wider range, the server 104 is able to manage theposition of the transmitting device 101 more accurately. Here, the moreaccurate management indicates management of the position of thetransmitting device 101 in a wider range. In other words, in order toincrease the range in which the position of the transmitting device 101can be managed, it is preferable that the transmitting device 101 andthe high sensitivity receiving device 102 be able to transmit andreceive the radio signal farther away (the communication coverage ofeach high sensitivity receiving device 102 be wider). Further, since thehigh sensitivity receiving devices 102 are installed at differentpositions, it is preferable that the number of high sensitivityreceiving devices 102 be large. Further, from a point of view ofusefulness, it is preferable to set an area in which the transmittingdevice 101 is likely to be located as the communication coverage of thehigh sensitivity receiving device 102.

Therefore, in the position notification system 100, as the number of thehigh sensitivity receiving devices 102 increases, qualities of servicesthat can be provided are further improved, which is preferable. In otherwords, it is possible to implement a more useful system at a lower cost.

Further, the high sensitivity receiving device 102 may be installed in amovable object (also referred to as a “mobile object”) such as avehicle, a motorbike, a bicycle, or the like. In other words, theposition of the high sensitivity receiving device 102 may be variable.

The network 103 is an arbitrary communication network and may beconfigured with either or both of a communication network of wiredcommunication and a communication network of radio communication.Further, the network 103 may be configured with one communicationnetwork or may be configured with a plurality of communication networks.For example, a communication network of any communication standard or acommunication path such as the Internet, a public telephone linenetwork, a wide area communication network for wireless mobile objectssuch as a so-called 3G line or a 4G line, a radio communication networkin which communication conforming to standards such as wide area network(WAN), local area network (LAN), and Bluetooth (a registered trademark)is performed, a communication path of near field communication (NFC) orthe like, a communication path of infrared communication, and acommunication network of a wired communication conforming to standardssuch as high-definition multimedia interface (HDMI (a registeredtrademark)) and universal serial bus (USB) may be included as thenetwork 103.

The server 104 and the terminal device 105 are information processingdevices which process information. The server 104 and the terminaldevice 105 are connected to the network 103 to be able to performcommunication and are able to perform communication with othercommunication devices connected to the network 103 via this network 103and exchange information.

In the position notification system 100, the number of transmittingdevices 101, the number of high sensitivity receiving devices 102, thenumber of servers 104, and the number of terminal devices 105 arearbitrary and may be two or more. For example, as illustrated in FIG. 5,the position notification system 100 is assumed to include N highsensitivity receiving devices 102 (N is an arbitrary natural number)installed at different positions (high sensitivity receiving devices102-1 to 102-N).

A timing at which the transmitting device 101 transmits the radio signal(position information) is arbitrary. For example, the transmittingdevice 101 may transmit the radio signal at regular intervals or when apredetermined event occurs (for example, in a case where it moves apredetermined distance, in a case where it becomes a predetermined time,or the like).

In this case, the radio signal transmitted from the transmitting device101 is received by the high sensitivity receiving device 102 locatednear the transmitting device 101. If the transmitting device 101transmits the radio signal within a communication coverage 121 of thehigh sensitivity receiving device 102-K (K is an integer of 1≤K≤N), thehigh sensitivity receiving device 102-K receives the radio signal,acquires the position information of the transmitting device 101, andsupplies the position information to the server 104 via the network 103(relays the position information).

For example, if the elderly person 111 (transmitting device 101) movesinto the communication coverage of another high sensitivity receivingdevice 102, and the transmitting device 101 transmits the radio signal,the high sensitivity receiving device 102 similarly relays the positioninformation. Therefore, as long as the elderly person 111 (thetransmitting device 101) is located within the communication coverage ofany one of the high sensitivity receiving devices 102, the user is ableto know the position of the elderly person 111.

The server 104 manages the position information of the transmittingdevice 101. In a case where there are a plurality of transmittingdevices 101, the server 104 manages the position information for eachtransmitting device 101. For example, the transmitting device 101transmits its own identification information (ID) together with theposition information. The server 104 stores and manages the positioninformation in association with the ID of the transmitting device 101.Therefore, the server 104 is able to provide only position informationof the transmitting device 101 requested from the user (terminal device105). Further, the server 104 is able to manage the user to whom theposition information is permitted to be provided for each transmittingdevice 101. In other words, the server 104 is able to provide theposition information of each transmitting device 101 only to the userwho is permitted to obtain the position information of the transmittingdevice 101.

Further, the server 104 may manage the position information of thetransmitting device 101 in association with information other than theID of the transmitting device 101. For example, the server 104 may storeand manage the position information of the transmitting device 101 inassociation with time information or the like. Accordingly, the server104 is able to manage and provide a history of the position informationof the transmitting device 101.

Further, the time information may be transmitted from the transmittingdevice 101. For example, the transmitting device 101 may transmit thetime information included in the GNSS signal together with the positioninformation as the radio signal.

Further, content of the position information transmitted by thetransmitting device 101 is arbitrary as long as the position informationtransmitted by the transmitting device 101 may be information that isable to be managed as information indicating the position of thetransmitting device 101 in the server 104. For example, the transmittingdevice 101 may transmit the GNSS signal (or the time informationincluded in the GNSS signal) without obtaining the position informationfrom the GNSS signal. In this case, the high sensitivity receivingdevice 102, the server 104, or the like may obtain the positioninformation of the transmitting device 101 using the GNSS signal or thetime information. Further, the information processing device (server orthe like) which obtains the position information of the transmittingdevice 101 may be separately installed by using the GNSS signal or thetime information.

Further, for example, the position of the transmitting device 101 may beobtained on the basis of the installation position of the highsensitivity receiving device 102 which receives the radio signal fromthe transmitting device 101. For example, in the example of FIG. 5, thetransmitting device 101 is located within the communication coverage 121of the high sensitivity receiving device 102. In this case, the server104 estimates that the transmitting device 101 is located within thecommunication coverage 121 of the high sensitivity receiving device102-K on the basis of the information relayed by the high sensitivityreceiving device 102-K and manages the estimation as the positioninformation. In other words, in this case, the position of thetransmitting device 101 is managed with the granularity of the number ofhigh sensitivity receiving devices 102 (the width of the communicationcoverage of each high sensitivity receiving device 102). In this case,the transmitting device 101 may transmit at least its own ID as theradio signal.

Further, for example, the server 104 may estimate a distance between thehigh sensitivity receiving device 102 and the transmitting device 101from radio wave strength of the radio signal received by the highsensitivity receiving device 102 and manage the distance as the positioninformation as well. In other words, the server 104 may manage the highsensitivity receiving device 102 in which the transmitting device 101 islocated in its communication coverage and the distance between the highsensitivity receiving device 102 and the transmitting device 101. Theestimation of the distance may be performed in the high sensitivityreceiving device 102 or the server 104 or may be performed by aseparately installed information processing device (server or the like).

Further, for example, in a case where the transmitting device 101 islocated in a portion where the communication coverages of a plurality ofhigh sensitivity receiving devices 102 overlaps, that is, in a casewhere the radio signal transmitted by the transmitting device 101 isrelayed by a plurality of high sensitivity receiving devices 102, theposition of the transmitting device 101 may be estimated using atrigonometric technique. For example, the estimation of the position maybe performed in the server 104 or may be performed by a separatelyinstalled information processing device (server or the like).

Each of the high sensitivity receiving devices 102 may be able to relayinformation of an arbitrary transmitting device 101 or may be able torelay only information of the transmitting device 101 corresponding toits own transmitting device. For example, information transmitted from acertain transmitting device 101 may be able to be relayed only by thehigh sensitivity receiving device 102 owned or managed by the owner (ormanager) of the transmitting device 101. The owner (or manager) mayinclude not only individuals but also companies. Accordingly, it ispossible to avoid the high sensitivity receiving device 102 from beingshared by a plurality of the users, and for example, it is possible tosuppress a reduction in safety of communication such as informationleakage or the like. Further, the number of available high sensitivityreceiving devices 102 may be set in accordance with an amount of feepaid by the user. Accordingly, it is possible to differentiate thequalities of services to be provided in accordance with a consideration.

<Transmitting Device>

Next, the transmitting device 101 will be described. A method ofperforming transmission and reception of the radio signal between thetransmitting device 101 and the high sensitivity receiving device 102 isarbitrary and may be performed in conformity with any communicationstandard. For example, it may be performed by a method capable ofperforming long distance communication using a frequency band including925 MHz (also referred to as a “920 MHz band”).

FIG. 6 is a block diagram illustrating a main configuration example ofthe transmitting device 101. The transmitting device 101 includes a CPU131, a BPSK modulating unit (π/2 BPSK modulation) 132, a chirpgenerating unit 133, a chirp modulating unit 134, a reference clockgenerating unit (TCXO 26 MHz) 135, a PLL 136, a high-efficiencyamplifying unit (PA) 137, an antenna 138, an antenna 139, a globalpositioning system (GPS) receiving unit 140, and a timing controller 141as illustrated in FIG. 6.

The CPU 131 performs an arbitrary process and control related totransmission. For example, the CPU 131 generates modulation data(including a synchronization signal) which is data for transmission andsupplies the modulation data to the BPSK modulating unit 132. Further,for example, the CPU 131 sets an initial value and an inclination of thechirp modulation and supplies the initial value and the inclination tothe chirp generating unit 133. The initial value of the chirp modulationis information such as the center frequency designating a channel(transmission channel) used for multiplexing the transmission signal. Asthe inclination of the chirp modulation, the same inclination is set tothe transmission signals to be multiplexed in the same channel.

For example, the transmission channel and the transmission timing ofeach transmission signal controlled by a signal output by the timingcontroller 141 as will be described later are set on the basis of theidentification information and the time of the transmitting device 101.For example, the CPU 131 obtains the transmission channel and thetransmission timing on the basis of the identification informationstored in a memory (not illustrated) in the transmitting device 101 andthe time indicated by the time information supplied from the GPSreceiving unit 140 and sets the transmission channel and thetransmission timing.

As will be described later, the high sensitivity receiving device 102holds the identification information of the transmitting device 101. Thesupply of the identification information of the transmitting device 101to the high sensitivity receiving device 102 is performed, for example,by the server 104. Upon receiving the transmission signal transmitted bythe transmitting device 101, the high sensitivity receiving device 102obtains a reception channel and a reception timing on the basis of theidentification information and the time of the transmitting device 101and uses the reception channel and the reception timing for reception ofthe transmission signal. The high sensitivity receiving device 102obtains the reception channel and the reception timing corresponding to(synchronized with) the transmission channel and the transmission timingusing a method similar to the method used for the transmitting device101 to obtain the transmission channel and the transmission timing.

As described above, the communication between the transmitting device101 and the high sensitivity receiving device 102 is synchronized usingthe channel and the timing obtained on the basis of at least theidentification information of the transmitting device 101 as the knowninformation.

Returning to the description of FIG. 6, for example, the CPU 131 obtainsa delay correction N and supplies the obtained delay correction N to thetiming controller 141 together with a transmission instruction. Further,the CPU 131 is driven on the basis of the time information extractedfrom the GPS signal received by the GPS receiving unit 140.

The BPSK modulating unit (π/2 BPSK modulation) 132 performsBPSK-modulation on the modulation data (including the synchronizationsignal) supplied from CPU 131 and supplies the resulting data to thechirp modulating unit 134. The chirp generating unit 133 generates achirp signal on the basis of the initial value and the inclination ofthe chirp modulation supplied from the CPU 131. The chirp generatingunit 133 supplies the generated chirp signal to the chirp modulatingunit 134.

The chirp modulating unit 134 modulates (chirp-modulates) theBPSK-modulated modulation data supplied from the BPSK modulating unit132 using the chirp signal supplied from the chirp generating unit 133.The chirp modulating unit 134 supplies the chirp-modulated modulationdata to the PLL 136 (a frequency dividing unit 151). The reference clockgenerating unit (TCXO 26 MHz) 135 generates a reference clock of 26 MHz.

The reference clock generating unit 135 supplies the generated referenceclock to the PLL 136 (a phase comparing unit (Φ) 152). The PLL 136generates a transmission signal of a frequency corresponding to thechirp modulated modulation data supplied from the chirp modulating unit134 and supplies the generated transmission signal to thehigh-efficiency amplifying unit 137. Under the control of the timingcontroller 141, the high-efficiency amplifying unit (PA) 137 amplifiesthe transmission signal (chirp-modulated transmission signal) suppliedfrom the PLL 136 and transmits the amplified transmission signal via theantenna 138 as the radio signal.

The GPS receiving unit 140 acquires the GPS signal transmitted from theGPS satellite via the antenna 139. The GPS receiving unit 140 suppliesthe time information included in the GPS signal to the CPU 131. Further,the GPS receiving unit 140 measures 1 pulse per second (PPS) from theGPS signal and notifies the timing controller 141 of a period of time of1 PPS.

The timing controller 141 supplies a control signal TX START to the BPSKmodulating unit 132, the chirp generating unit 133, and thehigh-efficiency amplifying unit 137, and controls (permits/prohibits)execution of processes thereof in accordance with the value. Further,the timing controller 141 performs such control on the basis of the GPSsignal. For example, the timing controller 141 performs such control onthe basis of information indicating 1 PPS supplied from the GPSreceiving unit 140. Further, the timing controller 141 also performssuch control on the basis of the transmission instruction supplied fromthe CPU 131. Further, the timing controller 141 corrects a provisiontiming of the control signal TX START using the delay correction Nsupplied from the CPU 131. The transmission timing of each transmissionsignal obtained by the chirp modulation is controlled in accordance withthe control signal TX START output by the timing controller 141.

As illustrated in FIG. 6, the PLL 136 includes the frequency dividingunit 151, the phase comparing unit 152, a low-pass filter (LPF) 153, anda voltage controlled oscillator (VCO) 154.

The frequency dividing unit 151 changes a frequency of the signal fedback from the VCO 154 with a magnification corresponding to thefrequency of the chirp-modulated modulation data input as settingfrequency data (frequency command word (FCW)) and supplies the changedfrequency to the phase comparing unit 152.

The phase comparing unit 152 compares a phase of the output of thefrequency dividing unit 151 with a phase of the reference clock suppliedfrom the reference clock generating unit 135, and supplies a comparisonresult to the LPF 153. The LPF 153 blocks unnecessary high frequencycomponents of the comparison result and supplies the filter processingresult to the VCO 154.

The VCO 154 controls an output frequency in accordance with an inputtedfilter processing result voltage of the LPF 153. The output (thetransmission signal) of the VCO 154 is supplied to the high-efficiencyamplifying unit 137. Further, the output of the VCO 154 is fed back tothe frequency dividing unit 151.

By using the phase shift keying modulation or the minimum deviationmodulation, it is possible to generate the transmission signal using thePLL having such a simple configuration, and thus it is possible tosuppress the increase in power consumption.

<BPSK Modulating Unit>

FIG. 7 is a block diagram illustrating a main configuration example ofthe BPSK modulating unit 132 of FIG. 6. As illustrated in FIG. 7, theBPSK modulating unit 132 includes a FIFO memory 161, a counter (counter512) 162, a flip flop 163, an EXNOR gate 164, a flip flop 165, a valueconverting unit 167, an up-sampling unit (UP sample X 512) 167, and anFIR filter 168. These are configured as illustrated in FIG. 7.

With this configuration, the BPSK modulating unit 132 performs BPSKmodulation on the modulation signal supplied from the CPU 131 on thebasis of the control signal TX START supplied from the timing controller141 and the reference clock (26 MHz) generated by the reference clockgenerating unit 135, and supplies the BPSK-modulated modulation data tothe chirp modulating unit 134.

<Chirp Generating Unit>

FIG. 8 is a diagram illustrating a main configuration example of thechirp generating unit 133 of FIG. 6. As illustrated in FIG. 8, the chirpgenerating unit 133 has a counter (counter 10 bits) 171, a comparingunit (compare) 172, an AND gate 173, and a counter (counter 20 bits)174. These are configured as illustrated in FIG. 8.

With this configuration, the chirp generating unit 133 is able togenerate the chirp signal on the basis of the initial value and theinclination of the chirp supplied from the CPU 131, the control signalTX START supplied from the timing controller 141, and the referenceclock (26 MHz) generated by the reference clock generating unit 135.

<Timing Controller>

FIG. 9 is a block diagram illustrating a main configuration example ofthe timing controller 141 in FIG. 6. As illustrated in FIG. 9, thetiming controller 141 includes a flip flop 181, a flip flop 182, an ANDgate 183, an OR gate 184, a flip flop 185, a flip flop 191, a flip flop192, a flip flop 183, an AND gate 194, an OR gate 195, a counter(Counter) 196, and a comparing unit (Compare) 197. These are configuredas illustrated in FIG. 9.

With this configuration, the timing controller 141 is able to generatethe control signal TX START on the basis of the transmission instructionor the delay correction supplied from the CPU 131, the informationindicating 1 PPS supplied from the GPS signal receiving unit 140, thereference clock (26 MHz) generated by the reference clock generatingunit 135, and supplies the control signal TX START to the respectiveprocessing units described above.

Further, an example of aspects of signals when the timing controller 141operates is illustrated in FIG. 10. As illustrated in FIG. 10, even whenthe transmission instruction is supplied, the value of the controlsignal TX START does not become “1” until a timing at which the countvalue is reset (a timing indicated by a dotted line in FIG. 10). Inother words, the transmission signal is not transmitted. In other words,the value of the control signal TX START is “1” at the timing at whichthe count value is reset. In other words, the transmission signal istransmitted at this timing. As described above, the timing controller141 is able to control the transmission timing of the transmissionsignal using the control signal TX START.

<Flow of Transmission Process>

Next, a process executed by the transmitting device 101 will bedescribed. First, an example of the flow of a transmission processexecuted when the transmitting device 101 transmits a packet will bedescribed with reference to the flowchart of FIG. 11.

If the transmission process is started, in step S101, the GPS receivingunit 140 receives the GPS signal via the antenna 139. The GPS receivingunit 140 supplies the information indicating 1 PPS to the timingcontroller 141 on the basis of the received GPS signal.

In step S102, the timing controller 141 determines whether or not it isthe grid timing (the grid time), that is, a timing known to thereception side. As described above, the known timing is obtained on thebasis of the identification information and the time of the transmittingdevice 101. In a case where it is determined not to be the grid timing,it is on standby until it becomes the grid timing. In a case where it isdetermined to be the grid timing (a known timing at which thetransmission instruction is received, and packet data can betransmitted), the process proceeds to step S103.

In step S103, the BPSK modulating unit 132 acquires the transmissiondata (modulation data including the synchronization signal) from the CPU131 and performs the BPSK modulation.

In step S104, the chirp modulating unit 134 chirp-modulates theBPSK-modulated transmission data obtained by the process of step S103using the chirp signal generated by the chirp generating unit 133. Thechirp modulation is performed such that a transmission signal of achannel which is obtained on the basis of the identification informationand the time of the transmitting device 101 and known to the receptionside is generated.

In step S105, the PLL 136 converts the chirp-modulated transmissionsignal obtained in step S104 into a transmission frequency.

In step S106, the high-efficiency amplifying unit 137 amplifies thetransmission signal converted into the transmission frequency. In stepS107, the high-efficiency amplifying unit 137 transmits the amplifiedtransmission signal via the antenna 138 as the radio signal.

If the process of step S107 is completed, the transmission process ends.

The transmitting device 101 executes the above-described transmissionprocess on data of each packet. Accordingly, the transmitting device 101is able to transmit a plurality of chirp-modulated transmission signalsat different transmission timings. As a result, the transmitting device101 is able to multiplex a plurality of chirp-modulated transmissionsignals so that they can be separated (with no interference). In otherwords, it is possible to multiplex the transmission signals in the samechannel of the 920 MHz band in Japan.

<High Sensitivity Receiving Device>

Next, the high sensitivity receiving device 102 will be described. FIG.12 is a diagram illustrating a main configuration example of the highsensitivity receiving device 102. As illustrated in FIG. 12, the highsensitivity receiving device 102 includes, for example, an antenna 201,a low noise amplifying unit 202, a band pass filter (BPF) 203, a carrieroscillating unit 204, a multiplying unit 205, an LPF 206, an AD 207, asynchronization signal generating unit 208, and a matched filter 209.Further, the high sensitivity receiving device 102 includes, forexample, an antenna 211, a reference clock generating unit (TCXO 26 MHz)212, a GPS receiving unit 213, a CPU 214, a timing controller 215, andan AND gate 216. Further, the high sensitivity receiving device 102includes a dechirping unit 221, an LPF 222, and a BPSK demodulating unit(BPSK decoder) 223.

The low noise amplifying unit 202 receives the radio signal (forexample, the transmission signal transmitted from the transmittingdevice 101) via the antenna 201, amplifies the reception signal, andsupplies the amplified reception signal to the BPF 203. The BPF 203removes an unnecessary frequency component from the reception signal andsupplies the resulting reception signal to the multiplying unit 205. Thecarrier oscillating unit 204 generates a carrier frequency signal of apredetermined frequency used for transmission and reception. Forexample, in a case where a signal transmitted at the 920 MHz band isreceived, the carrier oscillating unit 204 performs oscillation at 925MHz and supplies the oscillation signal (carrier signal) to themultiplying unit 205.

The multiplying unit 205 multiplies the reception signal supplied fromthe BPF 203 by the carrier signal supplied from the carrier oscillatingunit 204 and supplies the resulting reception signal to the LPF 206. TheLPF 206 cuts off a high frequency component of the reception signal andsupplies the resulting reception signal to the AD 207. The AD 207performs A/D conversion on the reception signal in which the highfrequency component is cut off, and supplies the resulting receptionsignal to the matched filter 209 and the dechirping unit 221.

The synchronization signal generating unit 208 generates a predeterminedsynchronization signal and supplies the generated synchronization signalto the matched filter 209. The matched filter 209 compares digital dataof the reception signal supplied from the AD 207 with the predeterminedsynchronization signal supplied from the synchronization signalgenerating unit 208 and supplies information indicating a comparisonresult to the AND gate 216.

The reference clock generating unit 212 generates a predeterminedreference clock and supplies the generated reference clock to the GPSreceiving unit 213. The GPS receiving unit 213 operates insynchronization with the reference clock and receives the GPS signal viathe antenna 211. The GPS receiving unit 213 supplies informationindicating 1 PPS to the timing controller 215 on the basis of the GPSsignal.

The CPU 214 obtains the delay correction N and supplies the delaycorrection N to the timing controller 215. The timing controller 215generates a gate signal for controlling a demodulation timing using theinformation indicating 1 PPS supplied from the GPS receiving unit 213and the delay correction N and supplies the gate signal to the AND gate216. In a case where the gate signal supplied from the timing controller215 and the information indicating the comparison result supplied fromthe matched filter 209 are both true (1), the AND gate 216 supplies acontrol signal for giving an instruction to start demodulation to thedechirping unit 221.

When the transmission signal is received, the CPU 214 obtains thereception channel and the reception timing on the basis of theidentification information of the transmitting device 101 stored in amemory (not illustrated) in the high sensitivity receiving device 102and the time indicated by the information included in the GPS signalreceived by the GPS receiving unit 213. The CPU 214 sets the obtainedreception channel and the reception timing in the respective units suchas the timing controller 215.

In a case where the instruction to start the demodulation is given fromthe AND gate 216, the dechirping unit 221 dechirps the digital data ofthe reception signal supplied from the AD 207 and supplies a dechirpresult to the LPF 222. The LPF 222 cuts off a high frequency componentof the dechirp result and supplies the dechirp result after the cut offto the BPSK demodulating unit 223. The BPSK demodulating unit 223performs the BPSK demodulation on the supplied information.

<Timing Controller>

FIG. 13 is a block diagram illustrating a main configuration example ofthe timing controller 215 of FIG. 12. As illustrated in FIG. 13, thetiming controller 215 has a flip flop 251, a flip flop 252, a flip flop253, a NAND gate 254, an OR gate 257, a counter (Counter) 258, and acomparing unit (Compare) 257. These are configured as illustrated inFIG. 13.

With this configuration, the timing controller 215 is able to generatethe gate signal on the basis of the information indicating 1 PPSsupplied from the GPS receiving unit 213, the reference clock suppliedfrom the reference clock generating unit 212, and the delay correction Nsupplied from the CPU 214.

Further, an example of aspects of the respective signals when the timingcontroller 215 operates is illustrated in FIG. 14. As illustrated inFIG. 14, the information indicating 1 PPS is in an ON state, and thegate signal is in an ON state for a predetermined period after a countvalue is reset. In other words, the reception signal is demodulated atthis timing. As described above, the timing controller 215 is able tocontrol the demodulation timing using the gate signal.

<Flow of Reception Process>

Next, a process executed by the high sensitivity receiving device 102will be described. First, an example of the flow of a reception processexecuted when the high sensitivity receiving device 102 receives apacket will be described with reference to the flowchart of FIG. 15.

If the reception process is started, in step S201, the low noiseamplifying unit 202 receives the transmission signal transmitted fromthe transmitting device 101 via the antenna 201. In step S202, the GPSreceiving unit 213 receives the GPS signal transmitted from the GPSsatellite via the antenna 211.

In step S203, the timing controller 215 determines whether or not acurrent time is the grid timing (known grid time) on the basis of theGPS signal received by the GPS receiving unit 213. In a case where thecurrent time is determined not to be the grid time, the process returnsto step S201, and the process of step S201 and subsequent steps isrepeated. Further, on the other hand, in a case where it is determinedin step S203 that the current time is the grid timing, the processproceeds to step S204.

In step S204, the dechirping unit 221 dechirps the reception signal. Instep S205, the BPSK demodulating unit 223 performs the BPSK demodulationon the dechirped reception signal.

If the process of step S205 ends, the reception process ends.

The high sensitivity receiving device 102 executes the above receptionprocess on data of each packet. As a result, the high sensitivityreceiving device 102 is able to dechirp a plurality of multiplexedchirp-modulated transmission signals transmitted at differenttransmission timings from the transmission side at timings correspondingto the respective transmission timings. Therefore, it is possible toseparate and demodulate the transmission signals (packets) (with nointerference). In other words, it is possible to implement multiplexingof the transmission signals in the same channel of the 920 MHz band inJapan.

2. Second Embodiment

<Application Example: Sharing of Reference Clock>

The configuration example of the transmitting device 101 according tothe first embodiment has been described with reference to FIG. 6. Here,the configuration of the transmitting device 101 is arbitrary and notlimited to this example. For example, the GPS receiving unit 140 mayoperate on the basis of a reference clock shared with the other units.

A main configuration example of the transmitting device 101 in this caseis illustrated in FIG. 16. As illustrated in FIG. 16, in this case, themain configuration is basically similar to the example of FIG. 6, but,for example, a reference clock generating unit 301 and a correcting unit302 are provided instead of the reference clock generating unit 135.

The reference clock generating unit 301 supplies the generated referenceclock to the respective processing units as in an example of FIG. 6. Thereference clock generating unit 301 also supplies the generatedreference clock to the GPS receiving unit 140.

In this case, the GPS receiving unit 140 operates on the basis of thereference clock. Here, the reference clock is considered to deviate fromthe time information included in the GPS signal. Therefore, the GPSreceiving unit 140 indicates the deviation of the reference clock fromthe time information included in the GPS signal as a frequency deviationof the reference clock, and supplies the frequency deviation of thereference clock to the CPU 131.

The CPU 131 generates frequency deviation correction data for correctingthe frequency deviation of the reference clock on the basis of thefrequency deviation of the reference clock. Further, the CPU 131supplies the frequency deviation correction data to the correcting unit302.

The correcting unit 302 corrects the modulation data chirp-modulated inthe chirp modulating unit 134 using the frequency deviation correctiondata supplied from the CPU 131.

As a result, it is possible to share the reference clock generating unitwithout increasing the error. Accordingly, it is possible to suppress anincrease in load and cost.

<Application Example: Chirp Signal>

Further, a transmission signal of one packet may be divided into aplurality of chirp signals as in an example illustrated in FIG. 17. Forexample, as illustrated in FIG. 17, a synchronization signal (Sync)known to the reception side and data (Payload) unknown to the receptionside may be alternately arranged in units of symbols serving as amodulation unit, and each symbol may undergo the chirp modulationindependently.

Further, in the above example, the frequency of the chirp signal hasbeen described as changing toward the high frequency over time, but thechange direction of the chirp signal is arbitrary. For example, thefrequency of the chirp signal may change toward the low frequencies overtime. Further, as illustrated in FIG. 18, for example, a chirp signalhaving a frequency changing toward the high frequency over time and achirp signal having a frequency changing towards the low frequency overtime may be mixed.

3. Third Embodiment

<Antitheft System>

In the above example, the position notification system 100 has beendescribed as an example, but the present technology can be applied toany communication system. For example, the transmitting device 101 maybe installed on a moving object or the like in addition to a person.

For example, the present technology can be applied to an antitheftsystem 800 for preventing theft of a vehicle, a motorbike, or the likeas illustrated in FIG. 19. In the case of the antitheft system 800, thetransmitting device 101 is installed in an object whose position ismonitored, for example, a vehicle 801 or a motorbike 802 owned by theuser. The transmitting device 101 informs the high sensitivity receivingdevice 102 of its position information (that is, the positioninformation of the vehicle 801 or the motorbike 802) appropriately,similarly to the example of the position notification system 100. Inother words, the user is able to access the server 104 from the terminaldevice 105 and know the position of the vehicle 801 or the motorbike 802as in the example of the position notification system 100. Therefore,since the user is able to know the position of the vehicle 801 or themotorbike 802 even in a case where it is stolen, it is possible toeasily find the vehicle 801 or the motorbike 802.

In the case of the antitheft system 800, similarly to the example of theposition notification system 100, the present technology can be appliedto the transmitting device 101 and the high sensitivity receiving device102. Further, by applying the present technology, it is possible tomultiplex the transmission signals in the same channel of the 920 MHzband.

<Other Communication Systems>

Further, information which is transmitted or received is arbitrary. Forexample, the CPU 131 of the transmitting device 101 may generatetransmission information including an image, an audio, measurement data,identification information of a device, parameter setting information,control information such as a command, or the like. Further, forexample, the transmission information may include two or more kinds ofinformation such as an image, an audio, identification information,setting information, and control information.

Further, for example, the CPU 131 may be able to generate transmissioninformation including information supplied from other devices. Forexample, the CPU 131 may be configured to generate transmissioninformation including information (sensor output) output from variouskinds of sensors which perform detection, measurement, or the like on anarbitrary variable such as an image, light, brightness, saturation,electricity, a sound, vibration, acceleration, a speed, an angularvelocity, force, a temperature (which is not a temperaturedistribution), humidity, a distance, an area, a volume, a shape, a flowrate, a time, magnetism, a chemical substance, smell, or the like or anamount of change thereof.

In other words, the present technology can be applied to systems usedfor arbitrary purposes such as 3D shape measurement, space measurement,object observation, movement deformation observation, biometricobservation, authentication processing, monitoring, autofocus, imagingcontrol, lighting control, tracking processing, input/output control,electronic device control, actuator control, or the like.

Further, the present technology can be applied to systems in arbitraryfields such as traffic, medical care, crime prevention, agriculture,livestock industry, mining, beauty, factory, household appliance,weather, natural surveillance, and the like. For example, the presenttechnology can also be applied to systems of capturing images providedfor viewing using digital cameras, mobile devices with a camerafunction, and the like. Further, for example, the present technology canalso be applied to systems used for traffic such as a vehicle system ofphotographing the front, the rear, the surroundings, the inside, and thelike of a vehicle for safe driving such as automatic stop or driverstate recognition, a monitoring camera system of monitoring travelingvehicles or roads, and a ranging system of measuring a distance betweenvehicles. Further, for example, the present technology can also beapplied to systems used for security using a surveillance camera forcrime prevention purposes, a camera for person authentication, and thelike. Further, for example, the present technology can also be appliedto systems used for sports using various kinds of sensors or the likewhich are able to be used for sports such as wearable cameras. Further,for example, the present technology can also be applied to systems usedfor agriculture using various kinds of sensors such as cameras formonitoring a state of fields and crops. Further, for example, thepresent technology can also be applied to systems used for livestockindustry using various kinds of sensors for monitoring the state oflivestock such as pigs and cattle. Further, the present technology canalso be applied to a system of monitoring a state of nature such asvolcanoes, forests, and oceans, a weather observation system ofobserving, for example, weather, temperature, humidity, wind speed,daylight hours, and the like, and a system of observing the ecology ofwildlife such as birds, fish, reptiles, amphibians, mammals, insects,and plants.

<Communication Device>

Further, a specification of the radio signal or information which istransmitted and received is arbitrary. Further, in the above example,the present technology has been described as being applied to thetransmitting device 101 and the high sensitivity receiving device 102,but the present technology can also be applied to an arbitrarytransmitting device, an arbitrary receiving device, and an arbitrarytransceiving device. In other words, the present technology can beapplied to an arbitrary communication device or an arbitrarycommunication system.

4. Fourth Embodiment

<Transmission and Reception of Radio Signal and Interference>

As described above, the radio signal is assumed to be transmitted andreceived at the 920 MHz band. In Japan, the 920 MHz band is a frequencyband released from July 2011 by the Ministry of Internal Affairs andCommunications, and anyone can use it without a license. However, amaximum continuous transmission time is limited to 4 seconds due to aregulation (association of radio industries and businesses (ARIB)) STDT-108). Further, if the continuous transmission time is shortened to,for example, 0.2 seconds, more channels can be allocated, andtransmission and reception can be performed with less interference.

Meanwhile, in a case where information is transmitted through a radiosignal, there is a method of transmitting and receiving the same packettwice or more in order to improve the S/N ratio of the reception signal.In an example of FIG. 20, a super frame of one minute is set, and thesame packet is transmitted ten times during that time. Since carriersensing is performed at the time of transmission, for example, the superframe of one minute is set for packet transmission of 10 times.

On the receiving side, if 10 packets are received, the packets aresynthesized to generate a synthetic signal, and data is extracted fromthe synthetic signal and output as illustrated in FIG. 21. Accordingly,the S/N ratio can be improved. For example, by adding 10 packets, it ispossible to improve the S/N ratio by about 10 dB. Therefore, since thereception can be performed even when the S/N ratio is low,longer-distance communication can be performed. Further, as describedabove, since the packet transmission time can be set to 0.2 seconds orless, more frequency channels can be used without being restricted bythe ARIB regulation.

For example, it is possible to perform frequency hopping using aplurality of carrier frequencies. FIG. 22 illustrates an example offrequency hopping. In the case of the example of FIG. 22, five channelsCH1 to CH5 are prepared, and one of the five channels is, for example,randomly selected and transmitted. Accordingly, it is possible tosuppress the occurrence of interference.

For example, if a plurality of transmitters (transmitters A to C)simultaneously transmit the radio signals at the same carrier frequencyas illustrated in FIG. 23, interference occurs at the receiver, and eachradio signal is unable to be correctly received. Therefore, by applyingfrequency hopping as in the example of FIG. 22, it is possible to reducea possibility that the carrier frequencies will be the same, and it ispossible to suppress the occurrence of interference accordingly.

However, even when this method is used, there is a possibility that thecarrier frequency will be the same as those of the other radio signals,and the occurrence of interference is unable to be completelysuppressed. For example, as illustrated in FIG. 24, a certain packettransmitted from the transmitter A and a certain packet transmitted fromthe transmitter B may have the same carrier frequency, and collision mayoccur. If such collision occurs, the packets may be unable to beseparated at the reception side. Therefore, if the interference signalis stronger, a packet in which the collision has occurred is replacedwith the interference signal side, and a signal error is likely tooccur.

For example, in FIG. 24, the receiver is assumed to receive the radiosignal transmitted from the transmitter A. Further, one of packetstransmitted from the transmitter A is assumed to collide with a packettransmitted from the transmitter B, and a radio signal transmitted fromthe transmitter B is assumed to be stronger than a radio signaltransmitted from the transmitter A. In this case, the receiversynthesizes the packet of the transmitter B in the collision hasoccurred as the packet transmitted from the transmitter A. Therefore, anerror is likely to occur in the synthetic signal, and data is unlikelyto be extracted. In this case, transmission and reception of 10 packetsin the super frame are likely to be all wasted.

In the case of bidirectional communication, it is possible to useidentification information or encourage retransmission by exchanginginformation with each other, but in the case of one-way communication,since information is unable to be supplied from the reception side tothe transmission side, countermeasures against such packet collision isunable to be taken basically.

<Position Notification System>

FIG. 25 is a diagram illustrating a main configuration example of aposition notification system which is one example of the signaltransmission/reception system to which the present technology isapplied. A position notification system 1100 illustrated in FIG. 25 is asystem in which a transmitting device 1101 gives a notification of itsposition.

The transmitting device 1101, a base station 1102, a cloud server 1103,and an information processing terminal 1104 illustrated in FIG. 25correspond to the transmitting device 101, the high sensitivityreceiving device 102, the server 104, and the terminal device 105 ofFIG. 4.

The transmitting device 1101 is an example of a transmitting device towhich the present technology is applied and transmits positioninformation indicating its position as a radio signal. The base station1102 is an example of a receiving device to which the present technologyis applied and receives the radio signal, acquires the positioninformation of the transmitting device 1101, and supplies the positioninformation or the like to the cloud server 1103. In other words, thebase station 1102 functions as a relay station which relays informationtransmitted from the transmitting device 1101 and transmits theinformation to the cloud server 1103. Transmission of information fromthe transmitting device 1101 to the base station 1102 is performed, forexample, through one-way communication. The cloud server 1103 managesvarious kinds of information such as the position information of eachtransmitting device 1101 and provides, for example, a service ofnotifying the user of the position of the transmitting device 1101. Forexample, the information processing terminal 1104 operated by the userwho desires to know the position of the transmitting device 1101accesses the cloud server 1103, acquires the position information of thetransmitting device 1101, and notifies the user of the position of thetransmitting device 1101, for example, by displaying the positioninformation together with map data or the like.

For example, the transmitting device 1101 is carried by a subject whomthe user desires to know the position such as an elderly person. Thetransmitting device 1101 is able to obtain its position information (forexample, a latitude and a longitude) appropriately, for example, byreceiving a GPS signal from a GPS satellite. The transmitting device1101 transmits its position information as the radio signalappropriately.

For example, in an example of FIG. 25, a transmitting device 1101-1 iscarried by an elderly person 1111-1 in Tokyo (Tokyo), a transmittingdevice 1101-2 is carried by an elderly person 1111-2 in Yokohama, and atransmitting device 1101-3 is carried by an elderly person 1111-3 inShizuoka.

Further, each transmitting device has identification information (ID).For example, in the example of FIG. 25, the identification informationof the transmitting device 1101-1 is 0001 (ID=0001), the identificationinformation of the transmitting device 1101-2 is 0002 (ID=0002), and theidentification information of the transmitting device 1101-3 is 0003(ID=0003). The identification information is registered in the cloudserver 1103.

Further, the position monitoring target is arbitrary. For example, theposition monitoring target may be a child, an animal such as a dog or acat, or an employee of a company. Three transmitting devices 1101 areillustrated in FIG. 25, but the number of transmitting devices 1101 isarbitrary. The transmitting device 1101 may be configured as a dedicateddevice or may be incorporated into, for example, a mobile informationprocessing device such as a mobile phone or a smartphone.

The base station 1102 may be any type of equipment. For example, thebase station 1102 may be a dedicated facility or structure. Further, forexample, the base station 1102 may be equipment which can be installedon a roof or a rooftop of a structure such as a general building, acondominium, a house, or the like. Further, for example, the basestation 1102 may be a mobile equipment which can be carried by the useror installed in a mobile object such as a vehicle.

A plurality of base stations 1102 are installed. For example, in theexample of FIG. 25, the base station 1102-1 is installed in Tokyo, andthe base station 1102-2 is installed in Fuji. In FIG. 25, two basestations 1102 are illustrated, but the number of base stations 1102 isarbitrary.

A configuration of the cloud server 1103 is arbitrary and may beconstituted by an arbitrary number of servers, an arbitrary number ofnetworks, and the like, for example. A plurality of cloud servers 1103may be provided.

In the position notification system 1100, the transmitting device 1101sets the frequency hopping on the basis of its identificationinformation ID. In other words, the transmitting device 1101 sets atransmission timing and a transmission frequency of each packet on thebasis of the identification information, and transmits each packet onthe basis of the setting. As described above, since transmission isperformed using frequency hopping, it is possible to suppress theoccurrence of interference. In other words, it is possible to performtransmission of information more reliably.

Further, by setting the transmission timing and the transmissionfrequency on the basis of the identification information of thetransmitting device 1101, it is possible to change the pattern of thetransmission timing and the transmission frequency for each transmittingdevice 1101, and thus it is possible to suppress the occurrence ofcollision with packets transmitted from the other transmitting devices1101. In other words, it is possible to perform transmission ofinformation more reliably.

Further, the base station 1102 acquires the identification informationof the transmitting device 1101 from the cloud server 1103 and performsreception on the basis of the identification information. In otherwords, the base station 1102 sets a reception timing and a receptionfrequency on the basis of the identification information, similarly tothe transmitting device 1101. If the transmission timing and thetransmission frequency of the packet is able to be identified by theidentification information, the packet is detected at the timing and thefrequency (that is, the reception timing and the reception frequency areadjusted to them), and thus even in a case where the S/N ratio is low,it is easier to detect the packet. Therefore, it is possible to performreception with higher sensitivity. In other words, more reliableinformation transmission can be implemented. Further, since a processsuch as packet detection need not be performed at an unnecessary timingand an unnecessary frequency band, it is possible to suppress anincrease in a load.

Further, in a case where a priority is assigned to the identificationinformation of the transmitting device 1101 acquired from the cloudserver 1103, the base station 1102 is able to implement more reliableinformation transmission by performing reception in accordance with thepriority.

Further, the base station 1102 supplies information related to receptionof the radio signal, for example, the transmitting device 1101 fromwhich the radio signal is received, content of the radio signal (dataextracted from the radio signal), and the like to the cloud server 1103as the reception information.

The cloud server 1103 registers and manages information related to thetransmitting device 1101 (also referred to as “terminal information”)and information related to the user (also referred to as “subscriberinformation”). The terminal information includes, for example, theidentification information of the transmitting device 1101, a mainlocation, and the like. Further, the subscriber information includes,for example, a name, an age, a sex, an address, information related topayment, identification information of a transmitting device to be used,a login ID, a password, and the like of the user (a person who receivesthe location notification service). It will be appreciated that theterminal information and the subscriber information may include anyinformation, and the present technology is not limited to the aboveexample.

Further, the cloud server 1103 transmits (supplies) the identificationinformation of the transmitting device 1101 to each base station 1102(some or all of the base stations 1102) via the network at apredetermined timing or in response to a request from the base station1102 or the like. At this time, the cloud server 1103 supplies theidentification information of the transmitting device 1101 whose radiosignal is likely to be received by the base station 1102 to each basestation 1102. In other words, the cloud server 1103 does not supply theidentification information of the transmitting device 1101 whose radiosignal is unlikely to be received by the base station 1102 to each basestation 1102. Accordingly, the base station 1102 is able to reduceunnecessary packet detection, and it is possible to suppress an increasein the load.

Further, as the number of transmitting devices 1101 in which the basestation 1102 is the reception target increases, a probability that thepacket collision will occur increases accordingly. More specifically,since a packet is unlikely to arrive from the transmitting device 1101whose radio signal is unlikely to be received, the probability that thepacket collision will actually occur does not increase. However, in thesetting of the reception timing and the reception frequency performed inthe base station 1102, the probability that the packet collision willoccur increases as the number of target transmitting devices 1101increases. In a case where the packet collision occurs in the setting ofthe reception timing and the reception frequency as described above, thereception of the packet is omitted. In other words, in a case where thetransmitting device 1101 whose radio signal is unlikely to be receivedis set as the reception target, reception sensitivity is unnecessarilyreduced, and reliability of information transmission is likely to beunnecessarily reduced. As described above, the base station 1102 is ableto exclude such a transmitting device 1101 from the reception targetsince the cloud server 1103 does not supply the identificationinformation of the transmitting device 1101 whose radio signal isunlikely to be received by the base station 1102, and thus it ispossible to suppress the reduction in the reception sensitivity andimplement more reliable information transmission.

Further, the cloud server 1103 acquires reception information from thebase station 1102. For example, the cloud server 1103 manages aninformation transmission/reception history between the transmittingdevice 1101 and the base station 1102 (for example, informationindicating the transmitting device 1101 which transmits the radio signaland the base station 1102 which receives the radio signal, when theradio signal is received, or the like) on the basis of the receptioninformation. The cloud server 1103 selects the transmitting device 1101that supplies the identification information to the base station 1102 onthe basis of the history. Accordingly, since it is possible to supplythe identification information of the transmitting device 1101 on thebasis of the previous communication history, it is possible to moreaccurately determine a possibility that each base station 1102 willreceive the radio signal of each transmitting device 1101. Therefore,each base station 1102 can implement more reliable informationtransmission.

Further, for example, the cloud server 1103 is able to provide theposition of the transmitting device 1101 (the elderly person 1111) tothe information processing terminal 1104 on the basis of the receptioninformation.

Further, the identification information of the transmitting device 1101may be supplied from the cloud server 1103 to the base station 1102 inany form. For example, the cloud server 1103 may supply theidentification information of the transmitting device 1101 to the basestation 1102 using a priority list. The priority list is informationincluding a list of identification information of the transmittingdevices 1101 whose radio signal is likely to be received by the basestation 1102 which is supplied with the priority list. For example, thecloud server 1103 may generate a priority list for the base station 1102and supplies the priority list to each base station 1102, and the basestation 1102 supplied with the priority list may perform a process ofreceiving the radio signal from the transmitting device 1101 indicatedin the priority list. Further, the reception priority (priority) in thebase station 1102 may be added to the identification information of thetransmitting device 1101 supplied to the base station 1102. For example,the priority list may include a priority of each piece of identificationinformation. Further, the base station 1102 supplied with the prioritylist may set a signal reception priority order or the like on the basisof the priority included in the priority list. Accordingly, the cloudserver 1103 is able not only to control the transmitting device 1101whose radio signal is received by the base station 1102 but also tocontrol the reception priority order.

<Cloud Server>

FIG. 26 is a block diagram illustrating a main configuration example ofthe cloud server 1103. A configuration of the cloud server 1103 isarbitrary as described above, and FIG. 26 illustrates that the cloudserver 1103 is configured as one computer. In this case, as illustratedin FIG. 26, the cloud server 1103 includes a central processing unit(CPU) 1151, a read only memory (ROM) 1152, and a random access memory(RAM) 1153 which are connected to one another via a bus 1154.

An input/output interface 1160 is also connected to a bus 1154. An inputunit 1161, an output unit 1162, a storage unit 1163, a communicationunit 1164, and a drive 1165 are connected to the input/output interface1160.

The input unit 1161 includes an arbitrary input device such as akeyboard, a mouse, a touch panel, an image sensor, a microphone, aswitch, an input terminal, or the like. The output unit 1162 includes anarbitrary output device such as a display, a speaker, an outputterminal, or the like. The storage unit 1163 includes an arbitrarystorage medium such as a non-volatile memory such as a hard disk, a RAMdisk, a solid state drive (SSD), a universal serial bus (USB) memory, orthe like. The communication unit 1164 includes a communication interfaceconforming to either or both of wired and wireless communicationstandards such as Ethernet (a registered trademark), Bluetooth (aregistered trademark), USB, high-definition multimedia interface (HDMI(a registered trademark)), or IrDA. The drive 1165 drives a removablemedium 1171 having an arbitrary storage medium such as a magnetic disk,an optical disk, a magneto-optical disk, or a semiconductor memory whichis loaded into the drive 1165.

In the cloud server 1103 having the above configuration, for example,the CPU 1151 is able to implement a function to be described later byloading a program stored in the storage unit 1163 onto the RAM 1153 viathe input/output interface 1160 and the bus 1154 and executing theprogram. The RAM 1153 also appropriately stores data and the likenecessary for the CPU 1151 to execute various kinds of processes.

For example, the program executed by the CPU 1151 may be recorded in theremovable medium 1171 serving as a package medium and applied. In thiscase, the removable medium 1171 may be loaded into drive 1165, and theprogram may be installed in the storage unit 1163 via the input/outputinterface 1160. Further, the program may be provided via a wired orwireless transmission medium such as a local area network, the Internet,or digital satellite broadcasting. In this case, the program may bereceived by the communication unit 1164 and installed in the storageunit 1163. Further, the program may be installed in the ROM 1152 or thestorage unit 1163 in advance.

In the cloud server 1103, the identification information identifying thetransmitting device (for example, the transmitting device 1101) whichtransmits the radio signal is supplied to the receiving device (forexample, the base station 1102) which receives the radio signal. Forexample, the cloud server 1103 includes a supplying unit which suppliesthe identification information identifying the transmitting device whichtransmits the radio signal to the receiving device that receives theradio signal. Accordingly, it is possible to implement more reliableinformation as described above.

<Function Block of CPU>

FIG. 27 is a functional block diagram illustrating a main configurationexample of functions implemented by the CPU 1151. As illustrated in FIG.27, the CPU 1151 includes functional blocks such as aterminal/subscriber information managing unit 1181, a priority listmanaging unit 1182, a reception information managing unit 1183, ahistory managing unit 1184, and a billing processing unit 1185. In otherwords, the CPU 1151 is able to execute a program and implement functionsindicated by the functional blocks.

The terminal/subscriber information managing unit 1181 performs aprocess related to registration and management of terminal informationand subscriber information. The priority list managing unit 1182performs a process related to generation, management, supply, and thelike of a priority list which is information including theidentification information of the transmitting device 1101 and thepriority of the transmitting device 1101. The reception informationmanaging unit 1183 performs a process related to acquisition,management, and the like of the reception information. The historymanaging unit 1184 performs a process related to management of acommunication history. The billing processing unit 1185 performs aprocess related to billing for service provision.

<Transmitting Device>

FIG. 28 is a diagram illustrating a main configuration example of thetransmitting device 1101. As illustrated in FIG. 28, the transmittingdevice 1101 includes a signal processing unit 1201 and a transmittingunit 1202. The signal processing unit 1201 performs a process such asthe generation of the transmission signal. The transmitting unit 1202performs a process related to the transmission of the transmissionsignal generated by the signal processing unit 1201. Further, thetransmitting unit 1202 transmits the same packet using the super frametwice or more as described above with reference to FIGS. 20 and 21.Further, the transmitting unit 1202 transmits each packet of the superframe using the frequency hopping as described above with reference toFIG. 22.

Further, the transmitting device 1101 includes a reference clockgenerating unit 1211, an antenna 1212, an acceleration sensor 1213, anantenna 1214, and an antenna 1215. The reference clock generating unit1211 generates the reference clock signal (ref.clock) and supplies thereference clock to the signal processing unit 1201 (a time informationgenerating unit 1222) and the transmitting unit 1202. The antenna 1212is an antenna for receiving the GPS signal. An acceleration sensor 1213is a sensor which detects acceleration (a motion, a posture, or thelike) of the transmitting device 1101. The acceleration sensor 1213supplies sensor information to the signal processing unit 1201 (a sensorcontrol unit (SCU) 1241). The antenna 1214 is an antenna for performingradio communication of a Bluetooth standard (Bluetooth communication).The antenna 1215 is an antenna for transmitting the radio signalgenerated by the transmitting unit 1202.

The signal processing unit 1201 includes an identification informationstorage unit 1221, the time information generating unit 1222, a Goldcode generating unit 1223, a transmission channel setting unit 1224, anda transmission timing setting unit 1225. Further, the signal processingunit 1201 includes a GPS receiving unit 1231, a forward error correction(FEC) 1232, a synchronization signal generating unit 1233, and amodulation data generating unit 1234. Further, the signal processingunit 1201 includes the SCU 1241, a Bluetooth module 1242, a CPU 1243,and a carrier sensing unit 1244.

The identification information storage unit (Device unique ID) 1221stores the identification information of the transmitting device 1101.The length of the identification information is arbitrary and may be,for example, 32 bits. The identification information storage unit 1221supplies the identification information to the Gold code generating unit1223 as seed information (seed 1) at a predetermined timing or inresponse to a request from the Gold code generating unit 1223.

The time information generating unit (Clock) 1222 generates timeinformation on the basis of the reference clock (ref.clock) suppliedfrom the reference clock generating unit 1211. The time information mayhave any specification and may be, for example, a coordinated universaltime (UTC). Further, the time information generating unit 1222 performscalibration of the generated time information using the time informationincluded in the GPS signal supplied from the GPS receiving unit 1231. Asa result, the time information generating unit 1222 is able to generatemore accurate time information. The time information generating unit1222 supplies the generated time information (for example, date: hour:minute (D: H: M)) to the Gold code generating unit 1223 as seedinformation (seed 2).

The Gold code generating unit (Random generator) 1223 generates a Goldcode which is a pseudo random number on the basis of the identificationinformation supplied from the identification information storage unit1221 and the time information supplied from the time informationgenerating unit 1222. The Gold code generating unit 1223 supplies thegenerated Gold code to the transmission channel setting unit 1224 andthe transmission timing setting unit 1225.

The transmission channel setting unit (Lookup table 1 Freq. channel)1224 sets a channel (transmission channel) for transmitting a packet.The transmission channel setting unit 1224 supplies the set transmissionchannel (Channel) to the transmitting unit 1202. The transmission timingsetting unit (Lookup table 2 Time slot) 1225 sets a timing (transmissiontiming) for transmitting a packet. The transmission timing setting unit1225 supplies the set transmission timing (Time Slot) to thetransmitting unit 1202. A specification of the transmission timing isarbitrary, and the transmission timing may be, for example, a Greenwichstandard time (GST).

In other words, the transmission channel setting unit 1224 and thetransmission timing setting unit 1225 set the frequency hopping forpacket transmission on the basis of the identification information andthe time information of the transmitting device 1101 (for example, FIG.22). As a result, since the transmission channel and the transmissiontiming of the packet are set in a pattern unique to the transmittingdevice 1101, it is possible to reduce a possibility that thetransmission channel and the transmission timing will be the same asthose of the other transmitting devices 1101, and it is possible tosuppress the occurrence of packet collision.

The GPS receiving unit 1231 receives the GPS signal transmitted from theGPS satellite via the antenna 1212. The GPS receiving unit 1231 suppliesthe received GPS signal to the time information generating unit 1222 asinformation (Calibration) for calibration of the time information.Further, the GPS receiving unit 1231 also supplies the GPS signal to thetransmitting unit 1202 as information (Time & Freq. Calibration) forcalibration of the time information and the frequency. Further, the GPSreceiving unit 1231 extracts the time information included in the GPSsignal and supplies the time information to the FEC 1232.

The FEC 1232 adds a forward error correction code to the timeinformation supplied from the GPS receiving unit 1231. The FEC 1232supplies the time information to which the forward error correction codeis added to the modulation data generating unit 1234 as data. In otherwords, this data is information unknown to the receiving side (forexample, the base station 1102).

The synchronization signal generating unit (Sync Pattern) 1233 generatesa synchronization signal for synchronization. The synchronization signalis configured with a signal of a predetermined synchronization pattern.The synchronization pattern is information known to the reception side(for example, the base station 1102). The synchronization signalgenerating unit 1233 supplies the generated synchronization signal tothe modulation data generating unit 1234.

The modulation data generating unit 1234 is controlled by the CPU 1243adds the synchronization signal supplied from the synchronization signalgenerating unit 1233 to the data supplied from the FEC 1232 andgenerates modulation data (Mod. data). In other words, the modulationdata generating unit 1234 generates data (a packet) to be transmitted.The modulation data generating unit 1234 supplies the modulation data tothe transmitting unit 1202 (a BPSK modulating unit 1251).

The SCU 1241 is controlled by the CPU 1243 and controls the accelerationsensor 1213, acquires sensor information (information related toacceleration) from the acceleration sensor 1213, and supplies the sensorinformation to the CPU 1243.

The Bluetooth module (Bluetooth module) 1242 is controlled by the CPU1243 and performs Bluetooth communication with other devices via theantenna 1214. For example, the Bluetooth module 1242 supplies thereceived information to the CPU 1243.

The CPU 1243 performs control related to packet transmission performedby the transmitting device 1101. For example, the CPU 1243 controls theoutput of the modulation data performed by the modulation datagenerating unit 1234 on the basis of the sensor information suppliedfrom the SCU 1241, the information supplied from the Bluetooth module1242, and a carrier sensing result supplied from the carrier sensingunit 1244. For example, the CPU 1243 prohibits the modulation data frombeing output in a case where other radio communication is beingperformed in a desired transmission channel as a result of carriersensing. In other words, the CPU 1243 permits or prohibits the packettransmission.

The carrier sensing unit 1244 performs the carrier sensing using areception signal having a limited band supplied from the transmittingunit 1202 (a filter unit 1262). In other words, the carrier sensing unit1244 detects the reception signal and checks whether or not any othercommunication is being performed in this frequency band (whether or notthe band is being used). The carrier sensing unit 1244 supplies thecarrier sensing result to the CPU 1243.

The transmitting unit 1202 includes the BPSK modulating unit 1251, anall-digital phase-locked loop (ADPLL) 1252, a frequency converting unit1253, and an amplifying unit 1254. Further, the transmitting unit 1202includes an amplifying unit 1261 and the filter unit 1262.

At the transmission timing set by the signal processing unit 1201 (thetransmission timing setting unit 1225). The BPSK modulating unit (π/2BPSK) 1251 performs the BPSK modulation on the modulation data (Mod.Data) supplied from the signal processing unit 1201 (the modulation datagenerating unit 1234) and supplies the resulting modulation data to theADPLL 1252.

An ADPLL 1252 generates a transmission signal of a frequencycorresponding to the BPSK-modulated modulation data supplied from theBPSK modulating unit 1251, and supplies the generated transmissionsignal to the frequency converting unit 1253.

The frequency converting unit 1253 synthesizes the transmission signalof the transmission channel set by the signal processing unit 1201 (thetransmission channel setting unit 1224) with the transmission signalsupplied from the ADPLL 1252, and converts the frequency band of thetransmission signal into the transmission channel. The frequencyconverting unit 1253 supplies the transmission signal to the amplifyingunit 1254.

The amplifying unit 1254 amplifies the transmission signal supplied fromthe frequency converting unit 1253 with a predetermined amplificationfactor and transmits the amplified transmission signal via the antenna1215 as the radio signal. In other words, the amplifying unit 1254transmits the transmission signal including the packet data through thetransmission channel set by the signal processing unit 1201 at thetransmission timing set by the signal processing unit 1201.

The amplifying unit 1261 receives the radio signal via the antenna 1215,amplifies the received radio signal (reception signal) with apredetermined amplification factor, and supplies the amplified receptionsignal to the filter unit 1262.

The filter unit (MIX) 1262 performs a filter process on the receptionsignal supplied from the amplifying unit 1261 to limit a frequency bandthereof. The filter unit 1262 supplies the reception signal having thelimited band to the signal processing unit 1201 (the carrier sensingunit 1244).

<Base Station>

FIG. 29 is a diagram illustrating a main configuration example of thebase station 1102. As illustrated in 29, the base station 1102 includesan antenna 1301, a low noise amplifying unit 1302, a BPF 1303, a carrieroscillating unit 1304, a multiplying unit 1305, a 90 degree shifter1306, a multiplying unit 1307, an analog/digital (A/D) converting a unit1308, a memory 1309, a CPU 1310, and a communication unit 1311. Further,the base station 1102 has an antenna 1321 and a GPS receiving unit 1322.

The low noise amplifying unit 1302 receives the radio signal (forexample, the transmission signal transmitted from the transmittingdevice 1101) via the antenna 1301, amplifies the reception signal, andsupplies the amplified reception signal to the BPF 1303. The BPF 1303removes an unnecessary frequency component from the reception signal andsupplies the resulting signal to the multiplying unit 1305 and themultiplying unit 1307. The carrier oscillating unit 1304 generates acarrier frequency signal of a predetermined frequency used fortransmission and reception. For example, in a case where a signaltransmitted at the 920 MHz band is received, the carrier oscillatingunit 1304 performs oscillation at the 920 MHz and supplies theoscillation signal (carrier signal) to the multiplying unit 1305 and the90 degree shifter 1306.

The multiplying unit 1305 multiplies the reception signal supplied fromthe BPF 1303 by the carrier signal supplied from the carrier oscillatingunit 1304 and generates a baseband In-Phase signal (an I signal). Themultiplying unit 1305 supplies the I signal to the A/D converting unit1308. The 90 degree shifter 1306 shifts the phase of the carrier signalsupplied from the carrier oscillating unit 1304 by 90°. The 90 degreeshifter 1306 supplies the phase-shifted carrier signal to themultiplying unit 1307. The multiplying unit 1307 multiplies thereception signal supplied from the BPF 1303 by the 90° phase-shiftedcarrier signal supplied from the 90 degree shifter 1306 and generate abaseband quadrature signal (a Q signal). The multiplying unit 1307supplies the Q signal to the A/D converting unit 1308.

The A/D converting unit 1308 performs A/D conversion on the supplied Isignal and the Q signal and supplies digital data to be stored in thememory 1309. It is preferable that a conversion rate of the A/Dconverting unit 1308 exceed the chip rate used for transmission. Forexample, in a case where transmission with a chip rate of 200 K/s isperformed with Δ=5 μs, it is necessary for the A/D converting unit 1308to perform the A/D conversion at a conversion rate of at least 200 KHzor more.

The memory 1309 includes a predetermined storage medium and acquiresdigital data of the I signal and the Q signal supplied from the A/Dconverting unit 1308, and stores the digital data in the storage medium.The storage medium may be any type of storage medium and may be, forexample, a semiconductor memory, a magnetic recording medium such as ahard disk, or any other storage medium. In a case where the A/Dconverting unit 1308 performs A/D conversion for 30 seconds at 8-bitaccuracy and a double conversion rate (400 KHz), the digital data of theI signal and the Q signal of 24 megabytes (24 Mbytes) are accumulated inthe memory 1309. Further, the memory 1309 is also able to store variouskinds of information (a program, data, or the like) supplied from theCPU 1310.

The CPU 1310 performs a process related to reception. For example, theCPU 1310 controls the communication unit 1311 such that theidentification information (LEID) of the transmitting device 1101 isacquired from the cloud server 1103 and stored in the memory 1309. Forexample, the CPU 1310 is able to acquire the priority list from thecloud server 1103.

Further, for example, the CPU 1310 reads information from the memory1309 and performs a process based on the information. For example, theCPU 1310 is able to read the identification information of thetransmitting device 1101 acquired from the cloud server 1103, perform,for example, the collision detection, the error correction, or the likeon the basis of the identification information, control the low noiseamplifying unit 1302 to the memory 1309, and control the reception.Further, the CPU 1310 is able to acquire, for example, the digital datareceived from the memory 1309 and perform a process related to thedemodulation of the digital data. Further, the CPU 1310 is able tosupply the demodulated data to the cloud server 1103 via thecommunication unit 1311 as the reception information. Further, thereception information may include information related to the receptionsuch as information related to a reception time, a reception channel,and a transmission source (the transmitting device 1101) in addition tothe demodulated data (content of the received information).

Further, for example, the CPU 1310 controls the GPS receiving unit 1322such that the GPS signal is received, acquires the time informationincluded in the GPS signal, and controls the reception on the basis ofthe time information. The CPU 1310 is able to execute other arbitraryprocesses.

The communication unit 1311 communicates with the cloud server 1103 andexchanges information.

The GPS receiving unit 1322 receives the GPS signal transmitted from theGPS satellite via the antenna 1321, and supplies the time informationincluded in the GPS signal to the CPU 1310.

<Function Blocks of CPU>

FIG. 30 is a functional block diagram illustrating a main configurationexample of functions implemented by the CPU 1310. As illustrated in FIG.30, the CPU 1310 has functional blocks such as a priority listprocessing unit 1331, a GPS processing unit 1332, a reception controlunit 1333, a reception information supplying unit 1334, a collisiondetecting unit 1335, a reception processing unit 1336, and an errorcorrecting unit 1337. In other words, the CPU 1310 is able to implementthe functions indicated by the functional blocks by executing a program.

The priority list processing unit 1331 performs a process related toacquisition of the priority list including the identificationinformation of the transmitting device 1101. The GPS processing unit1332 performs a process related to the GPS signal. The reception controlunit 1333 performs a process related to the reception control. Thereception information supplying unit 1334 performs a process related tothe supply of the reception information. The collision detecting unit1335 performs a process related to the packet collision detection. Thereception processing unit 1336 performs a process related to the packetreception. The error correcting unit 1337 performs a process related tothe error correction.

<Flow of Management Process>

Next, a process executed by the respective devices of the positionnotification system 1100 will be described. First, a process executed bythe cloud server 1103 will be described. The cloud server 1103 performsthe management process and performs processes such as registration,management, provision, or the like of various kinds of information. Anexample of the flow of the management process executed by the cloudserver 1103 will be described with reference to a flowchart of FIG. 31.

If the management process is started, in step S1101, theterminal/subscriber information managing unit 1181 receives the terminalinformation and the subscriber information via the communication unit1164, stores the terminal information and the subscriber information inthe storage unit 1163, and registers the terminal information and thesubscriber information. As the terminal information and the subscriberinformation, arbitrary information necessary for provision of theposition notification service is included. The terminal information isinformation related to the transmitting device 1101, and includes, forexample, the identification information, the main location, or the likeof the transmitting device 1101. Further, the subscriber informationincludes, for example, a name, an age, a sex, an address, informationrelated to payment, the identification information of the transmittingdevice to be used, a login ID, a password, and the like of the user (aperson who receives the location notification service). The terminalinformation and the subscriber information may be supplied from anydevice. For example, the terminal information and the subscriberinformation may be supplied from the transmitting device 1101 or may besupplied from other terminal devices. Further, the informationregistration may be performed as a contract for the positionnotification service or the like. In a case where the service provisionis for a fee, information necessary for billing is also registered.

In step S1102, the priority list managing unit 1182 generates thepriority list of each base station on the basis of the terminalinformation or the subscriber information registered in step S1101, thereception history of the base station 1102, and the like. The prioritylist is a list of transmitting devices 1101 in which a priority is givento reception and includes, for example, information such as theidentification information of the transmitting device 1101 and thepriority of the transmitting device 1101. The priority list managingunit 1182 generates the priority list corresponding to the base station1102 (the list of transmitting devices 1101 in which the base station1102 preferentially performs reception) for each base station 1102.

In step S1103, the priority list managing unit 1182 supplies thepriority lists generated in step S1102 to the base stations 1102corresponding to the lists via the communication unit 1164.

In step S1104, the reception information managing unit 1183 acquires thereception information supplied from the base station 1102. The historymanaging unit 1184 updates the history on the basis of the receptioninformation. The reception information is information related to thereception of the base station 1102. The content of the receptioninformation is arbitrary, and the reception information includes, forexample, received data, information related to the reception timing andthe reception channel, information related to the transmission source(the transmitting device 1101), and the like. The information related tothe transmission source includes at least the identification informationof the transmitting device 1101. The reception information managing unit1183 associates the reception information with other information, storesthe reception information in the storage unit 1163, and manages thereception information. For example, the reception information managingunit 1183 generates information indicating the position of thetransmitting device 1101 using the reception information and suppliesthe information to the information processing terminal 1104 or the likevia the communication unit 1164. Further, the history managing unit 1184generates the reception history of each base station 1102, stores thereception history in the storage unit 1163, and manages the receptionhistory. Further, the history managing unit 1184 updates the history tothe latest state on the basis of the reception information.

In step S1105, the billing processing unit 1185 performs a billingprocessing associated with the service provision.

If the process of step S1105 ends, the management process is performed.

Since the identification information of the transmitting device 1101 issupplied to the base station 1102 as described above, it is possible toperform the higher sensitivity reception in the base station 1102 andimplement more reliable information transmission. Further, it ispossible to suppress an increase in the load of the base station 1102.Further, since the priority lists corresponding to each base station1102 is supplied to each base station 1102 as described above, it ispossible to exclude the transmitting device 1101 whose radio signal isless likely to be received by each base station 1102 from the receptiontarget, and thus it is possible to suppress the reduction in thereception sensitivity in the base station 1102 and implement morereliable information transmission.

Further, for example, the priority list managing unit 1182 may generatethe priority list on the basis of a position relation between thetransmitting device 1101 and the base station 1102. In other words, thetransmitting device 1101 whose radio signal is received by the basestation 1102 may be set on the basis of the position relation betweenthe transmitting device 1101 and the base station 1102. For example, inthe example of FIG. 25, since the transmitting device 1101-1 is carriedby the elderly person 1111-1 in Tokyo, a possibility that the basestation 1102-2 in Fuji will receive the radio signal is low. Further,since the transmitting device 1101-3 is carried by the elderly person1111-3 in Shizuoka, a possibility that the base station 1102-1 in Tokyowill receive the radio signal is low. Therefore, the priority listmanaging unit 1182 supplies the priority list including theidentification information (0001) of the transmitting device 1101-1 andthe identification information (0002) of the transmitting device 1101-2to the base station 1102-1, and supplies the priority list including theidentification information (0002) of transmitting device 1101-2 and theidentification information of transmitting device 1101-3 (0003) to thebase station 1102-2. For example, in a case where the elderly person1111 moves to another area, the history is updated, and the prioritylist is updated. Accordingly, the latest priority list is provided toeach base station 1102.

Further, in the example of FIG. 25, the transmitting device 1101-2 iscarried by the elderly person 1111-2 in Yokohama. Therefore, theposition of the transmitting device 1101-2 from the base station 1102-1in Tokyo is farther than that of the transmitting device 1101-1.Further, the position of the transmitting device 1101-2 from the basestation 1102-2 in Fuji is farther than that of the transmitting device1101-3. Therefore, in the priority list for the base station 1102-1, thepriority of the transmitting device 1101-2 is set to be lower than thatof the transmitting device 1101-1. Further, in the priority list for thebase station 1102-2, the priority of the transmitting device 1101-2 isset to be lower than that of the transmitting device 1101-3. Forexample, in a case where these elderly person 1111 move to another area,the history is updated, and the priority is also updated. Accordingly,the latest priority is provided to each base station 1102.

Further, the setting of the priority list (the transmitting device 1101to be prioritized or the priority) may be performed using arbitraryinformation as a parameter. For example, the priority list may be set inaccordance with the position of the transmitting device 1101 (thedistance between the transmitting device 1101 and the base station 1102)in each time zone. Further, for example, the priority list may be set onthe basis of a communication specification, a communication capability,or the like of the transmitting device 1101 or the base station 1102.Further, for example, the priority list may be set on the basis of aservice associated with the transmitting device 1101 or the base station1102. In addition, the priority list may be set, for example, using anatural phenomenon such as weather, temperature, humidity, oratmospheric pressure, a behavior or preference of a monitoring subject,a history thereof, content or a history of communication, or a use state(congestion or the like) of a communication band. Further, of course, aplurality of parameters may be combined and used.

<Flow of Transmission Process>

Next, a process executed by the transmitting device 1101 will bedescribed. An example of the flow of a transmission process executed bythe transmitting device 1101 will be described with reference to aflowchart of FIG. 32.

If the transmission process is started, in step S1121, the transmissiontiming setting unit 1225 sets the packet transmission timing using theidentification information (device ID) of the transmitting device 1101.Further, the transmission channel setting unit 1224 sets the packettransmission frequency using the identification information (device ID)of the transmitting device 1101. In other words, the transmissionchannel setting unit 1224 and the transmission timing setting unit 1225set the frequency hopping. The transmission channel setting unit 1224and the transmission timing setting unit 1225 perform the setting on thebasis of the Gold code generated using the identification informationand the time information of the transmitting device 1101 as the seedinformation.

In step S1122, the GPS receiving unit 1231 receives the GPS signal,extracts the time information from the GPS signal, and generates thetransmission data.

In step S1123, the FEC 1232 adds the forward error correction code tothe transmission data generated in step S1122.

In step S1124, the transmitting unit 1202 determines whether or not itis the transmission timing. In a case where it is determined not to bethe transmission timing, it is on standby until it is determined to bethe transmission timing. Then, in a case where it is determined in stepS1124 that it is the transmission timing, the process proceeds to stepS1125.

In step S1125, the carrier sensing unit 1244 performs the carriersensing. In step S1126, the CPU 1243 determines whether or not thetransmission is able to be performed on the basis of the carrier sensingresult. In a case where the transmission is determined to be unable tobe performed, the process returns to step S1124, and the process of stepS1124 and subsequent steps is repeated. In a case where it is determinedin step S1126 that the transmission is unable to be performed, theprocess proceeds to step S1127.

In step S1127, the modulation data generating unit 1234 adds thesynchronization signal to the transmission data to which the forwarderror correction code is added in step S1123. Accordingly, since thesynchronization signal which is information known to the base station1102 is added, the base station 1102 is able to more easily detect thetransmission data. In other words, the base station 1102 is able toperform the reception with higher sensitivity.

In step S1128, the BPSK modulating unit 1251 performs the BPSKmodulation on the transmission data to which the synchronization signalis added in step S1127.

In step S1129, the ADPLL 1252 generates the transmission signal usingthe BPSK-modulated transmission data. Further, the frequency convertingunit 1253 converts the frequency band of the transmission signal intothe frequency band of the transmission frequency. The amplifying unit1254 amplifies the transmission signal of the transmission frequencyband and transmits the amplified transmission signal.

If the process of step S1129 ends, the transmission process ends.

Since the transmission timing and the transmission frequency are set onthe basis of the identification information of the transmitting device1101 as described above, the transmitting device 1101 is able tosuppress the occurrence of collision with packets transmitted from othertransmitting devices 1101 and perform the information transmission morereliably.

<Flow of Reception Process>

Next, a process executed by the base station 1102 will be described.First, an example of the flow of a reception process executed by thebase station 1102 will be described with reference to the flowchart ofFIG. 33.

If the reception process is started, in step S1141, the priority listprocessing unit 1331 acquires the priority list from the cloud server1103 via the communication unit 1311. The priority list transmitted fromthe cloud server 1103 is received by the communication unit 1311 andacquired by the priority list processing unit 1331.

In step S1142, the GPS processing unit 1332 receives the GPS signal andcorrects the time information using the GPS signal.

In step S1143, the reception control unit 1333 determines whether or notthe current time is a predetermined time and is on standby until apredetermined time comes. In a case where the current time is determinedto be a predetermined time, the process proceeds to step S1144.

In step S1144, the priority list processing unit 1331 sets the frequencyhopping of the packet transmitted from the transmitting device 1101(sets the reception timing and the reception frequency (a receptionchannel number Ch (ID, n) of all packets transmitted from thetransmitting device 1101) on the basis of the identification informationand the time information of the transmitting device 1101 for eachtransmitting device 1101 for which reception is expected on the basis ofthe priority list.

In step S1145, the reception control unit 1333 selects the unprocessedtransmitting device 1101. In step S1146, the reception control unit 1333receives the radio signal from the transmitting device 1101 of theprocessing target. At that time, the reception control unit 1333receives the radio signal (packet) in accordance with the setting of thefrequency hopping performed in step S1144. In step S1147, the receptioncontrol unit 1333 determines whether or not the reception process hasbeen performed for all the transmitting devices 1101. In a case where itis determined that there is an unprocessed transmitting device 1101, theprocess proceeds to step S1145. Further, in a case where it isdetermined in step S1147 that the reception process has been performedfor all the transmitting devices 1101, the process proceeds to stepS1148.

In step S1148, the reception information supplying unit 1334 suppliesthe reception information to the cloud server 1103 via the communicationunit 1311.

In a case where the process of step S1148 ends, the reception processends. Further, this process is a process corresponding to one sub frame.In other words, the reception process is repeated for each super frame.

<Flow of Reception Process>

Next, an example of the flow of the reception process on the radiosignal transmitted from the transmitting device 1101 of the processingtarget performed in step S1146 of FIG. 33 will be described withreference to the flowchart of FIG. 34.

If the reception process is started, in step S1161, the receptionprocessing unit 1336 initializes a waveform synthesizing buffer. In stepS1162, collision detecting unit 1335 performs the collision detection.In step S1163, the reception processing unit 1336 sets (initializes) avalue of a variable n indicating a number of a processing target packetto “0” (n=0). In other words, a first packet (n=0) is selected as theprocessing target. Further, the selection of the packet is equivalent tothe selection of the reception timing.

In step S1164, the reception processing unit 1336 detects a knownsynchronization pattern from the reception waveform for the packet ofn=0. In step S1165, the reception processing unit 1336 determineswhether or not the collision is not detected for the current packet(S(IDr,n)=0), and the synchronization pattern is successfully detected.In a case where it is determined that the collision is not detected, andthe synchronization pattern is successfully detected, the processproceeds to step S1166.

In step S1166, the reception processing unit 1336 adds the receptionwaveform to the waveform synthesizing buffer. If the process of stepS1166 ends, the process proceeds to step S1167. Further, in a case whereit is determined in step S1165 that the collision is detected(S(IDr,n)=1) or that the synchronization pattern fails to be detected,the process of step S1166 is skipped, and the process proceeds to stepS1167.

In step S1167, the reception processing unit 1336 determines whether ornot the value of the variable n is “9” (n=9). In a case where it isdetermined that the variable n does not reach 9 (there is a packet whichhas not been processed), the process proceeds to step S1168.

In step S1168, the reception processing unit 1336 increments the valueof the variable n by “+1” (n=n+1). In other words, the processing targetis updated to a next packet. If the process of step S1168 ends, theprocess returns to step S1164, and the process of step S1164 andsubsequent steps is performed. In other words, the process of step S1164to step S1168 is performed on each packet. Then, in a case where it isdetermined in step S1167 that the value of the variable n is “9” (n=9),that is, in a case where it is determined that all the packets have beenperformed, the process proceeds to step S1169.

In step S1169, the error correcting unit 1337 performs the errorcorrection on the reception waveform (synthesized waveform) synthesizedin the waveform synthesizing buffer. If the process of step S1169 ends,the reception process ends, and the process returns to FIG. 33.

<Collision Detection Process>

Next, an example of the flow of a collision detection process executedin step S1162 of FIG. 34 will be described with reference to a flowchartof FIG. 35.

In step S1181, the collision detecting unit 1335 initializes a variableS (IDr,n) indicating the occurrence of collision (S(IDr,n)=0).

In step S1182, the collision detecting unit 1335 sets a value of avariable k to “0” (k=0). The variable k indicates the transmittingdevice 1101 serving as the counterpart of the packet collision among thetransmitting devices 1101 (0 to M−1) for which reception is expected.

In step S1183, the collision detecting unit 1335 determines whether ornot IDr coincides with IDk. IDr indicates the identification informationof the transmitting device 1101 of the processing target. In otherwords, it is determined whether or not the processing target and thecollision counterpart are the same transmitting device 1101. If IDr doesnot coincide with IDk, the process proceeds to step S1184.

In step S1184, the collision detecting unit 1335 sets the value of thevariable n indicating the processing target packet to “0” (n=0).

In step S1185, the collision detecting unit 1335 determines whether ornot a reception channel (Ch(IDr,n)) of a packet n of the processingtarget of the transmitting device 1101 (IDr) of the processing targetcoincides with a reception channel (Ch(IDk,n)) of the packet n of theprocessing target of the transmitting device 1101 (IDk) of the collisioncounterpart (Ch(IDr,n)=Ch(IDk, n)?). In a case where they are determinedto coincide with each other (Ch (IDr, n)=Ch (IDk, n)), the processproceeds to step S1186.

In step S1186, the collision detecting unit 1335 detects the collision.In other words, the collision detecting unit 1335 sets the variable S(IDr,n) indicating the occurrence of collision to a value indicating theoccurrence of collision (S (IDr, n)=1). If the process of step S1186ends, the process proceeds to step S1187. Further, in a case where it isdetermined in step S1185 that the reception channel of the packet n ofthe processing target of the transmitting device 1101 of the processingtarget does not coincide with the reception channel of the packet n ofthe processing target of the transmitting device 1101 of the collisioncounterpart, the process proceeds to step S1187.

In step S1187, the collision detecting unit 1335 determines whether ornot the value of the variable n is “9” (n=9). In a case where the valueof variable n is determined not to reach “9”, that is, in a case whereit is determined that there is an unprocessed packet, the processproceeds to step S1188.

In step S1188, the collision detecting unit 1335 increments the value ofthe variable n by “+1” (n=n+1). In other words, the processing target isupdated to a next packet. If the process of step S1188 ends, the processreturns to step S1185, and the process of step S1185 and subsequentsteps is repeated. In other words, the process of step S1185 to stepS1188 is performed for each packet. Further, in a case where it isdetermined in step S1187 that the value of the variable n is “9”, thatis, in a case where it is determined that all the packets have beenprocessed, the process proceeds to step S1189. Further, in a case whereit is determined in step S1183 that IDr and IDk coincide with eachother, the collision detection is unnecessary, and thus the process ofstep S1184 to step S1188 is skipped, and the process proceeds to stepS1189.

In step S1189, the collision detecting unit 1335 determines whether ornot the value of the variable k is “M−1” (k=M−1). In a case where thevalue of the variable k is determined not to reach “M−1”, that is, in acase where it is determined that there is a transmitting device 1101 notselected as the collision counterpart, the process proceeds to stepS1190.

In step S1190, the collision detecting unit 1335 increments the value ofthe variable k by “+1” (k=k+1). In other words, a next transmittingdevice 1101 is selected as the collision counterpart. If the process ofstep S1190 ends, the process returns to step S1183, and the process ofstep S1183 and subsequent steps is repeated. In other words, the processof step S1183 to step S1190 is performed on each collision counterpart.Further, in a case where it is determined in step S1189 that the valueof the variable k is “M−1” (k=M−1), that is, in a case where it isdetermined that all the transmitting devices 1101 have been selected asthe collision opponent, the collision detection process ends, and theprocess returns to FIG. 34.

As the processes are performed as described above, it is possible tosuppress the increase in the load, perform the reception with highersensitivity, and implement more reliable information transmission.

The example of the priority list has been described above, but anyinformation may be included in the priority list. For example,information useful for reception of the radio signal may be included inthe priority list. For example, information related to a communicationformat such as the number of repeated transmissions, a radio modulationscheme, error correction, encryption (for example, the presence orabsence of encryption, designation of an encryption scheme, anencryption key, or the like), a transmission frequency, or the like maybe included. Accordingly, the base station 1102 is able to support aplurality of communication formats in addition to various communicationformats. Therefore, for example, the base station 1102 is able toreceive the radio signals transmitted from different transmittingdevices 1101 in different communication formats.

For example, even in a case where the transmitting device 1101-1 usedfor position detection of the elderly person sets the number of repeatedtransmissions to 10, and the transmitting device 1101-2 used forposition detection of a cat or a dog reduces the number of repeatedtransmissions to 4, the base station 1102 is able to appropriatelyreceive the radio signals from the respective transmitting devices 1101on the basis of the information of the number of repeated transmissionsof each transmitting device 1101 included in the priority list. In otherwords, since the base station 1102 is able to perform signal detectionunder the assumption that the number of repetitions is 10 for the radiosignal transmitted from the transmitting device 1101-1 is 10 and performsignal detection under the assumption that the number of repetitions ofthe radio signal transmitted from the transmitting device 1101-2 is 4,it is possible to receive any radio signal more efficiently and moreaccurately.

Further, the information useful for reception of the radio signal (forexample, the information related to the communication format) may bemanaged in association with the identification information of thetransmitting device 1101 which transmits the radio signal by the cloudserver 1103 or may be managed in another server. Further, theregistration of the information may be performed at an arbitrary timing.For example, the registration of the information may be performed whenthe terminal information, the subscriber information, or the like isregistered or at an arbitrary subsequent timing.

First Modified Example

In the communication between the transmitting device 1101 and the basestation 1102 of FIG. 25, the chirp modulation described above withreference to FIG. 3 and the like may be used.

In this case, the transmitting device 1101 sets the transmission channeland the transmission timing, for example, on the basis of its ownidentification information and time. Further, the transmitting device1101 performs the chirp modulation on the transmission data such as theposition information, multiplexes a plurality of obtained transmissionsignals in the same transmission channel by shifting the transmissiontiming, and transmits the multiplexed transmission signal. The BPSKmodulation and the like are also performed on the transmission dataappropriately.

On the other hand, the base station 1102 sets the reception channel andthe reception timing on the basis of the identification information andthe time of the transmitting device 101 included in the priority listtransmitted from the cloud server 1103. The base station 1102 receivesthe transmission signals multiplexed in a predetermined channel andacquires transmission data by dechirping the transmission signals. TheBPSK demodulation and the like are performed on the transmissionsignals.

As described above, the communication between the transmitting device1101 and the base station 1102 of FIG. 25 can be performed in accordancewith the scheme described as the first embodiment.

In the above example, the transmission of the transmission signal isprohibited in a case where it is detected that another radiocommunication is being performed in a desired transmission channel bythe carrier sensing, but a channel shifted by a predetermined bandwidthmay be newly set as the transmission channel, and the transmission ofthe transmission signal may be performed. In this case, for example, thecarrier sensing is also performed in the base station 1102.

For example, in a case where a predetermined channel is set as thetransmission channel and the reception channel in the transmittingdevice 1101 and the base station 1102, and the predetermined channel isused by another radio communication, a channel shifted by apredetermined bandwidth is newly set as the transmission channel and thereception channel in the transmitting device 1101 and the base station1102. In the transmitting device 1101 and the base station 1102, atiming shifted by a predetermined time may be newly set as thetransmission timing and the reception timing, and the communication maybe performed.

Second Modified Example

The identification information of the transmitting device 1101 servingas the transmission source of the transmission signal which is likely tobe received by the base station 1102 is included in the priority list ofeach base station, but the identification information of thetransmitting device 1101 newly added to the position notification systemmay be included in all the priority lists, and a notification indicatingthe identification information may be given to all the base stations1102.

The process of including the identification information of the newlyadded transmitting device 1101 in all the priority lists is performed,for example, until a signal transmitted by the communication device 1101is received by one of the base stations 1102.

FIG. 36 is a diagram illustrating an example of updating the prioritylist.

In this example, a transmitting device 1101 to which identificationinformation “ID 0100” is allocated is assumed to be newly added. Thecloud server 1103 is in a state in which it is difficult to manage thecommunication coverage of the base station 1102 in which thetransmitting device 1101 of “ID 0100” stays.

In this case, as illustrated in the upper part of FIG. 36, the cloudserver 1103 includes the identification information of “ID 0100” in allthe priority lists and transmits it to each base station.

In the example of FIG. 36, a priority list #1 is a priority list for thebase station 1102-1, and includes “ID 0100” which is the identificationinformation of the newly added transmitting device 1101 in addition to“ID 0010,” “ID 0011,” . . . . Similarly, a priority list #2 is apriority list for the base station 1102-2 and includes “ID 0100” whichis the identification information of the newly added transmitting device1101 in addition to “ID 0020,” “ID 0021,” . . . .

“ID 0010” and “ID 0011” included in the priority list #1 are theidentification information of the transmitting devices 1101 staying inthe communication coverage of the base station 1102-1. “ID 0020” and “ID0021” included in the priority list #2 are the identificationinformation of the transmitting devices 1101 staying in thecommunication coverage of the base station 1102-2.

In addition to the identification information of the transmitting device1101 staying in the communication coverage of each base station, thepriority list in which “ID 0100” serving as the identificationinformation of the newly added transmitting device 1101 is described istransmitted to the other base stations.

As a result, all the base stations 1102 are able to receive the signaltransmitted by the newly added transmitting device 1101 of “ID 0100.”

For example, in a case where the signal transmitted by the transmittingdevice 1101 of “ID 0100” is received by the base station 1102-1, thereceived information is transmitted to the cloud server 1103, thecommunication history of the base station 1102-1 is updated, and thepriority list of each base station is updated (FIG. 31). The updatedpriority list for each base station is transmitted to each base station.

In the updated priority list, “ID 0100” is included only in the prioritylist for the base station 1102-1 and deleted from the priority lists forthe other base stations as illustrated in the lower part of FIG. 36.

Since the management of the priority list is performed as describedabove, it is possible to add the transmitting device 1101 to theposition notification system later.

5. Fifth Embodiment

<Antitheft System>

In the above example, the position notification system 1100 has beendescribed by way of example, but the present technology can be appliedto an arbitrary communication system. For example, the transmittingdevice 1101 may be installed on a moving object or the like in additionto a person.

For example, the present technology can be applied to an antitheftsystem 1800 for preventing theft of a vehicle, a motorbike, or the likeas illustrated in FIG. 37. In the case of the antitheft system 1800, thetransmitting device 1101 is installed in an object whose position ismonitored, for example, a vehicle 1801 or a motorbike 1802 owned by theuser. The transmitting device 1101 informs the base station 1102 of itsposition information (that is, the position information of the vehicle1801 or the motorbike 1802) appropriately, similarly to the example ofthe position notification system 1100. In other words, the user is ableto access the server 1103 from the information processing terminal 1104and know the position of the vehicle 1801 or the motorbike 1802 as inthe example of the position notification system 1100. Therefore, sincethe user is able to know the position of the vehicle 1801 or themotorbike 1802 even in a case where it is stolen, it is possible toeasily find the vehicle 1801 or the motorbike 1802.

In the case of the antitheft system 1800, similarly to the example ofthe position notification system 1100, the present technology can beapplied to the transmitting device 1101 and the base station 1102.Further, by applying the present technology, it is possible to thereception rate.

<Other Communication Systems>

Further, the information transmitted and received is arbitrary. Forexample, the transmitting device 1101 may generate and transmittransmission information including an image, an audio, measurement data,identification information of a device, parameter setting information,control information such as a command, or the like. Further, forexample, the transmission information may include two or more kinds ofinformation such as an image, an audio, identification information,setting information, and control information.

Further, for example, the transmitting device 1101 may be able togenerate transmission information including information supplied fromother devices. For example, the transmitting device 1101 may beconfigured to generate and transmit transmission information includinginformation (sensor output) output from various kinds of sensors whichperform detection, measurement, or the like on an arbitrary variablesuch as an image, light, brightness, saturation, electricity, a sound,vibration, acceleration, a speed, an angular velocity, force, atemperature (which is not a temperature distribution), humidity, adistance, an area, a volume, a shape, a flow rate, a time, magnetism, achemical substance, smell, or the like or an amount of change thereof.

In other words, the present technology can be applied to systems usedfor arbitrary purposes such as 3D shape measurement, space measurement,object observation, movement deformation observation, biometricobservation, authentication processing, monitoring, autofocus, imagingcontrol, lighting control, tracking processing, input/output control,electronic device control, actuator control, or the like.

Further, the present technology can be applied to systems in arbitraryfields such as traffic, medical care, crime prevention, agriculture,livestock industry, mining, beauty, factory, household appliance,weather, natural surveillance, and the like. For example, the presenttechnology can also be applied to systems of capturing images providedfor viewing using digital cameras, mobile devices with a camerafunction, and the like. Further, for example, the present technology canalso be applied to systems used for traffic such as a vehicle system ofphotographing the front, the rear, the surroundings, the inside, and thelike of a vehicle for safe driving such as automatic stop or driverstate recognition, a monitoring camera system of monitoring travelingvehicles or roads, and a ranging system of measuring a distance betweenvehicles. Further, for example, the present technology can also beapplied to systems used for security using a surveillance camera forcrime prevention purposes, a camera for person authentication, and thelike. Further, for example, the present technology can also be appliedto systems used for sports using various kinds of sensors or the likewhich are able to be used for sports such as wearable cameras. Further,for example, the present technology can also be applied to systems usedfor agriculture using various kinds of sensors such as cameras formonitoring a state of fields and crops. Further, for example, thepresent technology can also be applied to systems used for livestockindustry using various kinds of sensors for monitoring the state oflivestock such as pigs and cattle. Further, the present technology canalso be applied to a system of monitoring a state of nature such asvolcanoes, forests, and oceans, a weather observation system ofobserving, for example, weather, temperature, humidity, wind speed,daylight hours, and the like, and a system of observing the ecology ofwildlife such as birds, fish, reptiles, amphibians, mammals, insects,and plants.

Further, a specification of the radio signal or information which istransmitted and received is arbitrary. Further, in the above example,the present technology has been described as being applied to thetransmitting device 1101, the base station 1102, the cloud server 1103,or the position notification system 1100 having them, but the presenttechnology can be applied to an arbitrary transmitting device, anarbitrary receiving device, an arbitrary transceiving device, anarbitrary communication device, an arbitrary information processingdevice, and an arbitrary system.

<Computer>

A series of processing described above can be executed by hardware or bysoftware. In a case where a series of processes is executed by software,it is preferable to have a configuration serving as a computer capableof executing the software. Examples of the computer include a computerincorporated in dedicated hardware and a general-purpose computercapable of executing an arbitrary function through various programsinstalled therein.

FIG. 38 is a block diagram illustrating a main configuration example ofa computer. As illustrated in FIG. 38, a computer 1900 has a centralprocessing unit (CPU) 1901, a read only memory (ROM) 1902, and a randomaccess memory (RAM) 1903 which are connected to one another via a bus1904.

An input/output interface 1910 is also connected to the bus 1904. Aninput unit 1911, an output unit 1912, a storage unit 1913, acommunication unit 1914, and a drive 1915 are connected to theinput/output interface 1910.

The input unit 1911 includes an arbitrary input device such as akeyboard, a mouse, a touch panel, an image sensor, a microphone, aswitch, an input terminal, or the like. The output unit 1912 includes anarbitrary output device such as a display, a speaker, an outputterminal, or the like. The storage unit 1913 includes an arbitrarystorage medium such as a non-volatile memory such as a hard disk, a RAMdisk, an SSD, a USB memory, and the like. The communication unit 1914includes a communication interface conforming to either or both of wiredand wireless communication standards such as Ethernet (a registeredtrademark), Bluetooth (a registered trademark), USB, HDMI (a registeredtrademark), or IrDA. The drive 1915 drives a removable medium 1921having any storage medium such as a magnetic disk, optical disk, amagneto-optical disk, or a semiconductor memory.

In the computer 1900 having the above configuration, for example, theCPU 1901 is able to implement a function equivalent to a part or all ofhardware configuration of each device described above by loading aprogram stored in the storage unit 1913 onto the RAM 1903 via theinput/output interface 1910 and the bus 1904 and executing the program.In other words, at least some of a series of processes described aboveis performed. The RAM 1903 also appropriately stores data and the likenecessary for the CPU 1901 to execute various kinds of processes.

For example, the program executed by the CPU 1901 may be recorded in theremovable medium 1921 serving as a package medium and applied. In thiscase, the removable medium 1921 may be loaded into drive 1915, and theprogram may be installed in the storage unit 1913 via the input/outputinterface 1910. Further, the program may be provided via a wired orwireless transmission medium such as a local area network, the Internet,or digital satellite broadcasting. In this case, the program may bereceived by the communication unit 1914 and installed in the storageunit 1913. Further, the program may be installed in the ROM 1902 or thestorage unit 1913 in advance.

Further, a part of the above-described series of processing is able tobe executed by hardware, and others is able to be executed by software.

<Others>

The embodiment of the present technology is not limited to theabove-described embodiments, and various modifications can be madewithout departing from the gist of the present technology.

Further, for example, the present technology can be applied to anyconfiguration constituting a device or a system, and for example, thepresent technology may be implemented as a processor serving as a systemlarge scale integration (LSI) or the like, a module using a plurality ofprocessors or the like, a unit using a plurality of modules or the like,or a set or the like in which other functions are further added to aunit (that is, some components of a device).

Further, in this specification, a “system” means a group of a pluralityof constituent elements (devices, modules, or the like), and allconstituent elements need not be necessarily in the same housing.Accordingly, a plurality of devices which are accommodated in separatehousings and connected to one another via a network or a single devicein which a plurality of modules are accommodated in one housing areregarded as a system.

Further, for example, a configuration described as a single device (or aprocessing unit) may be divided and configured as a plurality of devices(or processing units). On the contrary, configurations described as aplurality of devices (or processing units) in the above example may beconfigured as a single device (or processing unit). Further, aconfiguration not described above may be added to a configuration ofeach device (or each processing unit). Further, as long as aconfiguration or an operation of the entire system is substantially thesame, a part of a configuration of a certain device (or processing unit)may be included in a configuration of another device (or anotherprocessing unit).

Further, for example, the present technology may employ a configurationof cloud computing in which one function is shared and processed by aplurality of devices via a network.

Further, for example, the program described above may be executed in anarbitrary device. In this case, it is preferable for the device to havea necessary function (functional block or the like) and be able toobtain necessary information.

Further, for example, steps described in the above-described flowchartmay be executed by one device or shared and executed by a plurality ofdevices. Further, in a case where a plurality of processes are includedin one step, a plurality of processes included in the one step may beexecuted by one device or may be shared and executed by a plurality ofdevices.

Further, in a program executed by a computer, processes of stepsdescribing the program may be executed chronologically in the orderdescribed in this specification or may be executed in parallel orindividually at necessary timings such as called timings. In otherwords, as long as no contradiction arises, processes of steps may beexecuted in an order different from the above-described order. Further,a process of steps describing the program may be executed in parallelwith a process of another program or may be executed in combination witha process of another program.

Further, each of a plurality of present technologies described in thepresent specification may be implemented as a single technologyindependently as long as there is no contradiction. It will beappreciated that a plurality of arbitrary present technologies may beimplemented in combination with each other. For example, the presenttechnology described in any of the embodiments may be implemented incombination with the present technology described in another embodiment.Further, any of the present technologies described above may beimplemented in combination with other technologies not described above.

Further, the present technology may also have the followingconfigurations.

-   (1)

An information processing device, including:

a supplying unit that supplies a plurality of receiving devices withidentification information of a transmitting device, the plurality ofreceiving devices receiving information transmitted from thetransmitting device that multiplexes a plurality of transmission signalsgenerated by performing chirp modulation on transmission data in thesame transmission channel by shifting a transmission timing atpredetermined time intervals and transmits the multiplexed transmissionsignals, the identification information of the transmitting device beingused for a setting for receiving the transmission signals in each of thereceiving devices.

-   (2)

The information processing device according to (1), in which thesupplying unit supplies the identification information of thetransmitting device serving as a transmission source of the transmissionsignals receivable by each of the receiving devices.

-   (3)

The information processing device according to (2),

in which the supplying unit supplies the identification information onthe basis of a communication history of each of the receiving deviceswith the transmitting device.

-   (4)

The information processing device according to (3), further including,

a priority information managing unit that generates priority informationincluding the identification information of the transmitting device asthe transmission source of the transmission signals to be preferentiallyreceived on the basis of the communication history,

in which the supplying unit supplies the priority information to theplurality of receiving devices.

-   (5)

An information processing method, including:

supplying a plurality of receiving devices with identificationinformation of a transmitting device, the plurality of receiving devicesreceiving information transmitted from the transmitting device thatmultiplexes a plurality of transmission signals generated by performingchirp modulation on transmission data in the same transmission channelby shifting a transmission timing at predetermined time intervals andtransmits the multiplexed transmission signals, the identificationinformation of the transmitting device being used for a setting forreceiving the transmission signals in each of the receiving devices.

-   (6)

A transmitting device, including:

a chirp modulating unit that performs chirp modulation on transmissiondata;

a transmitting unit that multiplexes a plurality of transmission signalsgenerated by performing the chirp modulation in the same transmissionchannel by shifting a transmission timing at predetermined timeintervals and transmits the multiplexed transmission signals; and

a control unit that sets the transmission timing and the transmissionchannel on the basis of identification information of the transmittingdevice.

-   (7)

The transmitting device according to (6),

in which the control unit sets a known timing to a receiving device thatreceives the transmission signals on the basis of the identificationinformation as the transmission timing and sets a known channel as thetransmission channel.

-   (8)

The transmitting device according to (6) or (7),

in which an interval of the transmission timing is at least any one of afixed interval or an interval smaller than a chirp modulation cycle.

-   (9)

The transmitting device according to any of (6) to (8), furtherincluding,

a narrow band modulating unit that performs narrow band modulation onthe transmission data,

in which the chirp modulating unit performs the chirp modulation on thetransmission data which has undergone the narrow band modulation.

-   (10)

The transmitting device according to any of (6) to (9), furtherincluding,

a GPS signal receiving unit that receives a GPS signal,

in which the control unit sets the transmission timing and thetransmission channel on the basis of the identification information anda time included in the GPS signal.

-   (11)

The transmitting device according to any of (6) to (10),

in which the transmitting unit transmits the same packet as thetransmission signal twice or more.

-   (12)

A transmitting method, including steps of:

performing chirp modulation on transmission data;

multiplexing a plurality of transmission signals generated by performingthe chirp modulation in the same transmission channel by shifting atransmission timing at predetermined time intervals and transmitting themultiplexed transmission signals; and

setting the transmission timing and the transmission channel on thebasis of identification information of the transmitting device.

-   (13)

A receiving device, including:

a receiving unit that receives transmission signals transmitted from atransmitting device that multiplexes a plurality of transmission signalsgenerated by performing the chirp modulation in the same transmissionchannel by shifting a transmission timing at predetermined timeintervals and transmits the multiplexed transmission signals;

a dechirping unit that dechirps the transmission signals;

a control unit that sets a reception channel of the transmission signalson the basis of identification information of the transmitting deviceand sets a reception timing according to the transmission timing of eachof the plurality of transmission signals.

-   (14)

The receiving device according to (13), further including,

an acquiring unit that acquires the identification informationtransmitted from an information processing device different from thetransmitting device.

-   (15)

The receiving device according to (13) or (14),

in which the acquiring unit acquires a plurality of pieces ofidentification information, and

the control unit sets the reception channel and the reception timing foreach piece of identification information.

-   (16)

The receiving device according to any of (13) to (15),

in which an interval of the reception timing is at least any one of afixed interval or an interval smaller than a chirp modulation cycle.

-   (17)

The receiving device according to any of (13) to (16), furtherincluding,

a narrow band demodulating unit that performs narrow band demodulationon the dechirped transmission signals.

-   (18)

The receiving device according to any of (13) to (17), furtherincluding,

a GPS signal receiving unit that receives a GPS signal,

in which the control unit sets the reception timing and the receptionchannel on the basis of the identification information and a timeincluded in the GPS signal.

-   (19)

The receiving device according to any of (13) to (18),

in which the receiving unit receives the same packet twice or more,synthesizes a plurality of received packets, and extracts thetransmission data.

-   (20)

A receiving method, including:

receiving transmission signals transmitted from a transmitting devicethat multiplexes a plurality of transmission signals generated byperforming the chirp modulation in the same transmission channel byshifting a transmission timing at predetermined time intervals andtransmits the multiplexed transmission signals;

dechirping the transmission signals;

setting a reception channel of the transmission signals on the basis ofidentification information of the transmitting device and sets areception timing according to the transmission timing of each of theplurality of transmission signals.

REFERENCE SIGNS LIST

-   100 Position notification system-   101 Transmitting device-   102 High sensitivity receiving device-   103 Network-   104 Server-   111 Elderly person-   131 Central processing unit (CPU)-   132 Binary phase shift keying (BPSK) modulating unit-   133 Chirp generating unit-   134 Chirp modulating unit-   135 Reference clock generating unit-   136 Phase locked loop (PLL)-   137 High-efficiency amplifying unit-   140 Global positioning system (GPS) receiving unit-   141 Timing controller-   208 Synchronization signal generating unit-   209 Matched filter-   212 Reference clock generating unit-   213 GPS receiving unit-   214 CPU-   215 Timing controller-   216 AND gate-   221 Dechirping unit-   223 BPSK demodulating unit-   301 Reference clock generating unit-   302 Correcting unit-   800 Antitheft system-   1100 Position notification system-   1101 Transmitting device-   1102 Base station-   1103 Cloud server-   1104 Information processing terminal-   1151 CPU-   1181 Terminal/subscriber information managing unit-   1182 Priority list managing unit-   1183 Reception information managing unit-   1184 History managing unit-   1185 Billing processing unit-   1201 Signal processing unit-   1202 Transmitting unit-   1221 Identification information storage unit-   1222 Time information generating unit-   1223 Gold code generating unit-   1224 Transmission channel setting unit-   1225 Transmission timing setting unit-   1301 Antenna-   1302 Low noise amplifying unit-   1303 Band pass filter (BPF)-   1304 Carrier oscillating unit-   1305 Multiplying unit-   1306 90 degree shifter-   1307 Multiplying unit-   1308 Analog/digital (A/D) converting unit-   1309 Memory-   1310 CPU-   1321 Antenna-   1322 GPS receiving unit-   1331 Priority list processing unit-   1332 GPS processing unit-   1333 Reception control unit-   1334 Reception information supplying unit-   1335 Collision detecting unit-   1336 Reception processing unit-   1337 Error correcting unit-   1800 Antitheft system

The invention claimed is:
 1. A transmitting device, comprising: a chirpmodulating unit that performs chirp modulation on transmission data; atransmitting unit that multiplexes a plurality of transmission signalsgenerated by performing the chirp modulation in the same transmissionchannel by shifting a transmission timing at predetermined timeintervals and transmits the multiplexed transmission signals; and acontrol unit that sets the transmission timing and the transmissionchannel on the basis of identification information of the transmittingdevice.
 2. The transmitting device according to claim 1, wherein thecontrol unit sets a known timing to a receiving device that receives thetransmission signals on the basis of the identification information asthe transmission timing and sets a known channel as the transmissionchannel.
 3. The transmitting device according to claim 1, wherein aninterval of the transmission timing is at least any one of a fixedinterval or an interval smaller than a chirp modulation cycle.
 4. Thetransmitting device according to claim 1, further comprising, a narrowband modulating unit that performs narrow band modulation on thetransmission data, wherein the chirp modulating unit performs the chirpmodulation on the transmission data which has undergone the narrow bandmodulation.
 5. The transmitting device according to claim 1, furthercomprising, a GPS signal receiving unit that receives a GPS signal,wherein the control unit sets the transmission timing and thetransmission channel on the basis of the identification information anda time included in the GPS signal.
 6. The transmitting device accordingto claim 1, wherein the transmitting unit transmits the same packet asthe transmission signal twice or more.
 7. The transmitting deviceaccording to claim 1, wherein the identification information of thetransmitting device includes a unique device identifier (ID) of thetransmitting device.
 8. A transmitting method, comprising steps of:performing chirp modulation on transmission data; multiplexing aplurality of transmission signals generated by performing the chirpmodulation in the same transmission channel by shifting a transmissiontiming at predetermined time intervals and transmitting the multiplexedtransmission signals; and setting the transmission timing and thetransmission channel on the basis of identification information of thetransmitting device.
 9. The transmitting method, according to claim 8,wherein the identification information of the transmitting deviceincludes a unique device identifier (ID) of the transmitting device. 10.A receiving device, comprising: a receiving unit that receivestransmission signals transmitted from a transmitting device thatmultiplexes a plurality of transmission signals generated by performingthe chirp modulation in the same transmission channel by shifting atransmission timing at predetermined time intervals and transmits themultiplexed transmission signals; a dechirping unit that dechirps thetransmission signals; a control unit that sets a reception channel ofthe transmission signals on the basis of identification information ofthe transmitting device and sets a reception timing according to thetransmission timing of each of the plurality of transmission signals.11. The receiving device according to claim 10, further comprising, anacquiring unit that acquires a second identification informationtransmitted from an information processing device different from thetransmitting device.
 12. The receiving device according to claim 10,wherein the acquiring unit acquires a plurality of pieces ofidentification information, and the control unit sets the receptionchannel and the reception timing for each piece of identificationinformation.
 13. The receiving device according to claim 10, wherein aninterval of the reception timing is at least any one of a fixed intervalor an interval smaller than a chirp modulation cycle.
 14. The receivingdevice according to claim 10, further comprising, a narrow banddemodulating unit that performs narrow band demodulation on thedechirped transmission signals.
 15. The receiving device according toclaim 10, further comprising, a GPS signal receiving unit that receivesa GPS signal, wherein the control unit sets the reception timing and thereception channel on the basis of the identification information and atime included in the GPS signal.
 16. The receiving device according toclaim 10, wherein the receiving unit receives the same packet twice ormore, synthesizes a plurality of received packets, and extracts thetransmission data.
 17. The receiving device according to claim 11,wherein the identification information of the transmitting deviceincludes a unique device identifier (ID) of the transmitting device, andwherein the second identification information of the informationprocessing device includes a unique device identifier (ID) of theinformation processing device.
 18. A receiving method, comprising:receiving transmission signals transmitted from a transmitting devicethat multiplexes a plurality of transmission signals generated byperforming the chirp modulation in the same transmission channel byshifting a transmission timing at predetermined time intervals andtransmits the multiplexed transmission signals; dechirping thetransmission signals; setting a reception channel of the transmissionsignals on the basis of identification information of the transmittingdevice and sets a reception timing according to the transmission timingof each of the plurality of transmission signals.
 19. The receivingmethod according to claim 18, wherein the identification information ofthe transmitting device includes a unique device identifier (ID) of thetransmitting device.